diff --git a/apps/desktop/electron/main.cjs b/apps/desktop/electron/main.cjs
index 5d1f35ba450..9974ead119a 100644
--- a/apps/desktop/electron/main.cjs
+++ b/apps/desktop/electron/main.cjs
@@ -6031,19 +6031,32 @@ ipcMain.handle('hermes:pet-overlay:close', async () => {
 
   return { ok: true }
 })
-// Drag: the overlay reports a new absolute screen position (it already knows the
-// pointer's screen coords), we just move the window.
+// Drag/resize: the overlay reports new absolute screen bounds (it already knows
+// the pointer's screen coords). Drag keeps the size constant; the wheel-to-scale
+// gesture grows/shrinks it so the sprite is never cropped by the window edge.
+// The window is created non-resizable (no stray edge-drag on the transparent
+// frameless panel), which on Windows/Linux also blocks programmatic setBounds
+// sizing — so briefly flip resizable on whenever the size actually changes.
 ipcMain.on('hermes:pet-overlay:set-bounds', (_event, bounds) => {
   if (!petOverlayWindow || petOverlayWindow.isDestroyed() || !bounds) {
     return
   }
 
-  petOverlayWindow.setBounds({
-    x: Math.round(bounds.x),
-    y: Math.round(bounds.y),
-    width: Math.max(80, Math.round(bounds.width)),
-    height: Math.max(80, Math.round(bounds.height))
-  })
+  const win = petOverlayWindow
+  const width = Math.max(80, Math.round(bounds.width))
+  const height = Math.max(80, Math.round(bounds.height))
+  const [curW, curH] = win.getSize()
+  const resizing = width !== curW || height !== curH
+
+  if (resizing && !win.isResizable()) {
+    win.setResizable(true)
+  }
+
+  win.setBounds({ x: Math.round(bounds.x), y: Math.round(bounds.y), width, height })
+
+  if (resizing) {
+    win.setResizable(false)
+  }
 })
 // Click-through: the overlay window is a full rectangle but only the pet pixels
 // should be interactive. The renderer toggles this as the cursor enters/leaves
diff --git a/apps/desktop/src/app/desktop-controller.tsx b/apps/desktop/src/app/desktop-controller.tsx
index d36e63fe74f..c1e731f8d68 100644
--- a/apps/desktop/src/app/desktop-controller.tsx
+++ b/apps/desktop/src/app/desktop-controller.tsx
@@ -46,7 +46,8 @@ import {
 import { $paneOpen } from '../store/panes'
 import { respondToApprovalAction } from '../store/native-notifications'
 import { setPetActivity } from '../store/pet'
-import { setPetOverlayOpenAppHandler, setPetOverlaySubmitHandler } from '../store/pet-overlay'
+import { setPetScale } from '../store/pet-gallery'
+import { setPetOverlayOpenAppHandler, setPetOverlayScaleHandler, setPetOverlaySubmitHandler } from '../store/pet-overlay'
 import { $filePreviewTarget, $previewTarget, closeActiveRightRailTab } from '../store/preview'
 import {
   $activeGatewayProfile,
@@ -939,6 +940,8 @@ export function DesktopController() {
   submitTextRef.current = submitText
   const resumeSessionRef = useRef(resumeSession)
   resumeSessionRef.current = resumeSession
+  const requestGatewayRef = useRef(requestGateway)
+  requestGatewayRef.current = requestGateway
 
   useEffect(() => {
     if (isSecondaryWindow()) {
@@ -946,6 +949,9 @@ export function DesktopController() {
     }
 
     setPetOverlaySubmitHandler(text => void submitTextRef.current(text))
+    // Alt+wheel resize from the popped-out pet — persist it through this
+    // window's gateway (the overlay has none) so it survives restart.
+    setPetOverlayScaleHandler(scale => setPetScale(requestGatewayRef.current, scale))
     // Mail icon: $sessions is ordered most-recent-first; the pet is global (not
     // per session) so "most recent" is the right target. main.cjs already raised
     // the window before forwarding this.
@@ -960,6 +966,7 @@ export function DesktopController() {
     return () => {
       setPetOverlaySubmitHandler(null)
       setPetOverlayOpenAppHandler(null)
+      setPetOverlayScaleHandler(null)
     }
   }, [])
 
diff --git a/apps/desktop/src/app/pet-overlay/pet-overlay-app.tsx b/apps/desktop/src/app/pet-overlay/pet-overlay-app.tsx
index 1fcd21169f0..062001fbb49 100644
--- a/apps/desktop/src/app/pet-overlay/pet-overlay-app.tsx
+++ b/apps/desktop/src/app/pet-overlay/pet-overlay-app.tsx
@@ -1,12 +1,24 @@
 import { useStore } from '@nanostores/react'
-import { useEffect, useRef, useState } from 'react'
+import { useCallback, useEffect, useRef, useState } from 'react'
 
 import { PetBubble } from '@/components/pet/pet-bubble'
 import { PetSprite } from '@/components/pet/pet-sprite'
+import { usePetZoomGesture } from '@/components/pet/use-pet-zoom-gesture'
 import { Mail } from '@/lib/icons'
 import { $petActivity, $petInfo, setPetInfo } from '@/store/pet'
+import { overlayWindowSize } from '@/store/pet-overlay'
 import { setAwaitingResponse, setBusy } from '@/store/session'
 
+// Fallbacks mirror pet-sprite's defaults; the gateway normally sends real values.
+const DEFAULT_FRAME_W = 192
+const DEFAULT_FRAME_H = 208
+const DEFAULT_SCALE = 0.33
+
+// A sprite pixel counts as "solid" (interactive) at/above this alpha (0-255).
+// Low enough to catch anti-aliased edges, high enough that the faint halo around
+// the art still clicks through.
+const ALPHA_HIT_THRESHOLD = 16
+
 /**
  * The pop-out overlay's only view: a transparent, draggable mascot with a mini
  * composer.
@@ -81,12 +93,53 @@ export function PetOverlayApp() {
     return off
   }, [])
 
-  // Click-through: make only the sprite (or an open composer) interactive. With
-  // ignore+forward, the renderer still receives mousemove so we can re-enable
-  // hit-testing the moment the cursor returns to the pet.
+  // Click-through: make only the *solid* sprite pixels (plus the bubble / mail
+  // button / open composer) interactive — clicks on the transparent rectangle
+  // around the art pass through to whatever's behind. With ignore+forward, the
+  // renderer still receives mousemove so we can re-arm the moment the cursor
+  // returns to a solid pixel.
   useEffect(() => {
     setIgnore(true)
 
+    // True when the point sits on a solid sprite pixel or on the pet's other
+    // interactive chrome (bubble, mail button). Over the canvas we sample the
+    // rendered alpha; elsewhere inside the pet (bubble/button) we trust DOM
+    // hit-testing. Anything else is transparent backdrop.
+    const isInteractiveAt = (x: number, y: number): boolean => {
+      const pet = petRef.current
+      const target = document.elementFromPoint(x, y)
+
+      if (!pet || !target || !pet.contains(target)) {
+        return false
+      }
+
+      if (!(target instanceof HTMLCanvasElement)) {
+        return true
+      }
+
+      const rect = target.getBoundingClientRect()
+
+      if (rect.width === 0 || rect.height === 0) {
+        return true
+      }
+
+      const ctx = target.getContext('2d')
+
+      if (!ctx) {
+        return true
+      }
+
+      const px = Math.floor((x - rect.left) * (target.width / rect.width))
+      const py = Math.floor((y - rect.top) * (target.height / rect.height))
+
+      try {
+        return ctx.getImageData(px, py, 1, 1).data[3] >= ALPHA_HIT_THRESHOLD
+      } catch {
+        // Tainted/zero-size read — fail open so the pet stays grabbable.
+        return true
+      }
+    }
+
     const onMove = (ev: MouseEvent) => {
       if (dragRef.current || composerOpenRef.current) {
         setIgnore(false)
@@ -94,15 +147,7 @@ export function PetOverlayApp() {
         return
       }
 
-      const el = petRef.current
-
-      if (!el) {
-        return
-      }
-
-      const r = el.getBoundingClientRect()
-      const over = ev.clientX >= r.left && ev.clientX <= r.right && ev.clientY >= r.top && ev.clientY <= r.bottom
-      setIgnore(!over)
+      setIgnore(!isInteractiveAt(ev.clientX, ev.clientY))
     }
 
     window.addEventListener('mousemove', onMove)
@@ -231,6 +276,52 @@ export function PetOverlayApp() {
     window.hermesDesktop?.petOverlay?.control({ type: 'open-app' })
   }
 
+  // Alt+wheel over the popped-out pet resizes it. The overlay has no gateway,
+  // so paint the new scale locally for instant feedback, then ask the main
+  // renderer to persist it (it pushes the reconciled scale back). The window
+  // itself is grown to fit by the effect below.
+  const onScale = useCallback((next: number) => {
+    setPetInfo({ ...$petInfo.get(), scale: next })
+    window.hermesDesktop?.petOverlay?.control({ scale: next, type: 'scale' })
+  }, [])
+
+  usePetZoomGesture(petRef, onScale, Boolean(info.enabled && info.spritesheetBase64))
+
+  // Grow/shrink the OS overlay window to fit the pet at its current scale so the
+  // sprite is never cropped — covers both the wheel gesture here and a scale
+  // changed from the app's settings slider (pushed in as a state update). The
+  // pet renders bottom-center, so anchor the window's bottom-center while
+  // resizing (it stays put; only the transparent headroom changes). New bounds
+  // are persisted so the pet reopens at the right size.
+  useEffect(() => {
+    if (!info.enabled || !info.spritesheetBase64) {
+      return
+    }
+
+    const { width, height } = overlayWindowSize(
+      info.frameW ?? DEFAULT_FRAME_W,
+      info.frameH ?? DEFAULT_FRAME_H,
+      info.scale ?? DEFAULT_SCALE
+    )
+
+    const curW = window.outerWidth
+    const curH = window.outerHeight
+
+    if (width === curW && height === curH) {
+      return
+    }
+
+    const bounds = {
+      height,
+      width,
+      x: Math.round(window.screenX + (curW - width) / 2),
+      y: Math.round(window.screenY + (curH - height))
+    }
+
+    window.hermesDesktop?.petOverlay?.setBounds(bounds)
+    window.hermesDesktop?.petOverlay?.control({ bounds, type: 'bounds' })
+  }, [info.enabled, info.spritesheetBase64, info.scale, info.frameW, info.frameH])
+
   if (!info.enabled || !info.spritesheetBase64) {
     return null
   }
diff --git a/apps/desktop/src/components/pet/floating-pet.tsx b/apps/desktop/src/components/pet/floating-pet.tsx
index 2ceba5ac0c8..424a55c4e3d 100644
--- a/apps/desktop/src/components/pet/floating-pet.tsx
+++ b/apps/desktop/src/components/pet/floating-pet.tsx
@@ -4,7 +4,7 @@ import { useCallback, useEffect, useRef, useState } from 'react'
 import { useGatewayRequest } from '@/app/gateway/hooks/use-gateway-request'
 import { persistString, storedString } from '@/lib/storage'
 import { $petInfo, clearPetUnread, type PetInfo, petProfile, setPetInfo } from '@/store/pet'
-import { resetPetGallery } from '@/store/pet-gallery'
+import { resetPetGallery, setPetScale } from '@/store/pet-gallery'
 import { $petOverlayActive, initPetOverlayBridge, popOutPet, restorePetOverlay } from '@/store/pet-overlay'
 import { $activeGatewayProfile, normalizeProfileKey } from '@/store/profile'
 import { $gatewayState } from '@/store/session'
@@ -12,6 +12,7 @@ import { isSecondaryWindow } from '@/store/windows'
 import { useTheme } from '@/themes/context'
 
 import { PetSprite } from './pet-sprite'
+import { usePetZoomGesture } from './use-pet-zoom-gesture'
 
 // v2: positions are now top/left anchored (v1 stored bottom-anchored values,
 // which dragged inverted). Bumping the key discards stale v1 coordinates.
@@ -105,6 +106,7 @@ export function FloatingPet() {
   // speech bubble (a container child) never renders flipped/backwards.
   const spriteWrapRef = useRef<HTMLDivElement | null>(null)
   const petW = (info.frameW ?? 192) * (info.scale ?? 0.33)
+  const petH = (info.frameH ?? 208) * (info.scale ?? 0.33)
   // Soft contact shadow, sized off the pet so every scale/species grounds the
   // same way (cf. lairp's per-actor feet ellipse). Lighter on light backgrounds.
   const shadowW = Math.round(petW * 0.55)
@@ -115,6 +117,16 @@ export function FloatingPet() {
   // state is only committed on release.
   const dragRef = useRef<{ dx: number; dy: number; x: number; y: number } | null>(null)
 
+  // Keep the *whole* pet on-screen at its current size, so growing it near an
+  // edge can't leave the window cropping it. Shared by drag + the reclamp effect.
+  const clamp = useCallback(
+    ({ x, y }: Point): Point => ({
+      x: Math.min(Math.max(0, x), Math.max(0, (window.innerWidth || 800) - petW)),
+      y: Math.min(Math.max(0, y), Math.max(0, (window.innerHeight || 600) - petH))
+    }),
+    [petW, petH]
+  )
+
   // Fetch pet.info on connect. Poll quickly while inactive so an in-app
   // `/pet <slug>` appears, then slowly while active so regenerated spritesheets
   // and row-count metadata replace the cached base64 payload.
@@ -235,12 +247,13 @@ export function FloatingPet() {
     restorePetOverlay()
   }, [active])
 
-  // A window resize must never strand the pet off-screen — re-clamp the
-  // committed position (and persist it) whenever the viewport shrinks.
+  // Never strand or crop the pet: re-clamp (and persist) whenever the viewport
+  // shrinks or the pet's own size changes (wheel/slider). `clamp` carries the
+  // current size, so depending on it covers both triggers.
   useEffect(() => {
-    const onResize = () =>
+    const reclamp = () =>
       setPosition(prev => {
-        const next = clampToViewport(prev)
+        const next = clamp(prev)
 
         if (next.x === prev.x && next.y === prev.y) {
           return prev
@@ -251,10 +264,11 @@ export function FloatingPet() {
         return next
       })
 
-    window.addEventListener('resize', onResize)
+    reclamp()
+    window.addEventListener('resize', reclamp)
 
-    return () => window.removeEventListener('resize', onResize)
-  }, [])
+    return () => window.removeEventListener('resize', reclamp)
+  }, [clamp])
 
   const onPointerDown = useCallback((e: React.PointerEvent) => {
     const el = containerRef.current
@@ -289,7 +303,7 @@ export function FloatingPet() {
         return
       }
 
-      const next = clampToViewport({ x: e.clientX - drag.dx, y: e.clientY - drag.dy })
+      const next = clamp({ x: e.clientX - drag.dx, y: e.clientY - drag.dy })
       drag.x = next.x
       drag.y = next.y
       // Mutate the DOM directly — no setState, so no re-render while dragging. The
@@ -302,7 +316,7 @@ export function FloatingPet() {
         spriteWrapRef.current.style.transform = facing(next.x, petW)
       }
     },
-    [petW]
+    [clamp, petW]
   )
 
   const onPointerUp = useCallback((e: React.PointerEvent) => {
@@ -323,6 +337,12 @@ export function FloatingPet() {
     }
   }, [])
 
+  // Alt+wheel over the pet resizes it, persisting to `display.pet.scale` through
+  // the same path as the settings slider, so the two agree. Growing it re-runs
+  // the reclamp effect above (via `clamp`), so it never ends up cropped.
+  const onScale = useCallback((next: number) => setPetScale(requestGateway, next), [requestGateway])
+  usePetZoomGesture(containerRef, onScale, active && !overlayActive)
+
   // While popped out, the desktop overlay window owns the mascot — hide the
   // in-window one so there aren't two.
   if (!info.enabled || !info.spritesheetBase64 || overlayActive) {
diff --git a/apps/desktop/src/components/pet/pet-sprite.tsx b/apps/desktop/src/components/pet/pet-sprite.tsx
index 455f6a956aa..fe2e0a6daaf 100644
--- a/apps/desktop/src/components/pet/pet-sprite.tsx
+++ b/apps/desktop/src/components/pet/pet-sprite.tsx
@@ -117,7 +117,9 @@ function PetSpriteImpl({ info, zoom = 1, stateOverride, rowOverride }: PetSprite
       return
     }
 
-    const ctx = canvas.getContext('2d')
+    // willReadFrequently: the pop-out overlay samples this canvas's alpha under
+    // the cursor (per-pixel click-through), so opt into the CPU-readback path.
+    const ctx = canvas.getContext('2d', { willReadFrequently: true })
 
     if (!ctx) {
       return
diff --git a/apps/desktop/src/components/pet/use-pet-zoom-gesture.ts b/apps/desktop/src/components/pet/use-pet-zoom-gesture.ts
new file mode 100644
index 00000000000..0b10864e3ea
--- /dev/null
+++ b/apps/desktop/src/components/pet/use-pet-zoom-gesture.ts
@@ -0,0 +1,46 @@
+import { type RefObject, useEffect } from 'react'
+
+import { $petInfo } from '@/store/pet'
+import { nextScaleFromWheel } from '@/store/pet-gallery'
+
+/**
+ * Wire Alt/Option+wheel-to-scale onto a pet element: hold Alt and scroll up to
+ * grow the pet, down to shrink — identical on Mac and Windows. The modifier is
+ * required so a plain scroll over the pet still scrolls the page underneath
+ * (we only `preventDefault` while Alt is held).
+ *
+ * Native + non-passive so the conditional `preventDefault` actually takes (and
+ * keeps Electron from treating the gesture as a page zoom). Scale is read live
+ * from `$petInfo` so rapid steps compound without re-binding the listener.
+ *
+ * `ready` must track whether the pet element is actually rendered (both callers
+ * return null until a pet is enabled). It's a dependency so the listener
+ * (re)binds the moment the element mounts — `ref.current` changing alone would
+ * never re-run the effect.
+ */
+export function usePetZoomGesture<T extends HTMLElement>(
+  ref: RefObject<T | null>,
+  onScale: (scale: number) => void,
+  ready: boolean
+): void {
+  useEffect(() => {
+    const el = ref.current
+
+    if (!el || !ready) {
+      return
+    }
+
+    const onWheel = (event: WheelEvent) => {
+      if (!event.altKey) {
+        return
+      }
+
+      event.preventDefault()
+      onScale(nextScaleFromWheel($petInfo.get().scale, event.deltaY))
+    }
+
+    el.addEventListener('wheel', onWheel, { passive: false })
+
+    return () => el.removeEventListener('wheel', onWheel)
+  }, [ref, onScale, ready])
+}
diff --git a/apps/desktop/src/store/pet-gallery.ts b/apps/desktop/src/store/pet-gallery.ts
index d5aa9ea7d52..40d629552fe 100644
--- a/apps/desktop/src/store/pet-gallery.ts
+++ b/apps/desktop/src/store/pet-gallery.ts
@@ -333,6 +333,21 @@ export const PET_SCALE_MAX = 3.0
 export const PET_SCALE_DEFAULT = 0.33
 export const clampPetScale = (n: number) => Math.max(PET_SCALE_MIN, Math.min(PET_SCALE_MAX, n))
 
+// Wheel → scale. Multiplicative so one notch feels the same at any size. Tuned
+// for a discrete mouse-wheel notch (deltaY ≈ ±100); trackpad two-finger scroll
+// (smaller deltas) just resizes more gently, which is fine.
+const WHEEL_SCALE_K = 0.0015
+
+/**
+ * Next pet scale for one mouse-wheel step over the pet. Scrolling up (deltaY < 0)
+ * grows it, scrolling down shrinks it; the result is clamped to the slider's range.
+ */
+export function nextScaleFromWheel(current: number | undefined, deltaY: number): number {
+  const base = current ?? PET_SCALE_DEFAULT
+
+  return clampPetScale(base * Math.exp(-deltaY * WHEEL_SCALE_K))
+}
+
 let scalePersist: ReturnType<typeof setTimeout> | undefined
 
 /**
diff --git a/apps/desktop/src/store/pet-overlay.ts b/apps/desktop/src/store/pet-overlay.ts
index 3fda5e83b3c..1ab1b64ad23 100644
--- a/apps/desktop/src/store/pet-overlay.ts
+++ b/apps/desktop/src/store/pet-overlay.ts
@@ -55,6 +55,7 @@ export type PetOverlayControl =
   | { type: 'bounds'; bounds: PetOverlayBounds }
   | { type: 'open-app' }
   | { type: 'toggle-app' }
+  | { type: 'scale'; scale: number }
 
 // Persisted across restarts: was the pet popped out, and where on the desktop
 // did the user leave it. Keyed v1; bump if the bounds shape ever changes.
@@ -103,10 +104,24 @@ const OVERLAY_PAD_Y = 200
 const OVERLAY_MIN_W = 240
 const OVERLAY_MIN_H = 300
 
+/**
+ * Window bounds (width/height) that fully contain the pet at a given scale, plus
+ * the padding for its bubble/composer/drag margins. The single source of truth
+ * for both the initial pop-out size and the live wheel-to-scale resize, so the
+ * sprite is never cropped by the window edge no matter how big it's scaled.
+ */
+export function overlayWindowSize(frameW: number, frameH: number, scale: number): { width: number; height: number } {
+  return {
+    width: Math.max(OVERLAY_MIN_W, Math.round(frameW * scale + OVERLAY_PAD_X)),
+    height: Math.max(OVERLAY_MIN_H, Math.round(frameH * scale + OVERLAY_PAD_Y))
+  }
+}
+
 let stateUnsubs: Array<() => void> = []
 let controlUnsub: (() => void) | null = null
 let submitHandler: ((text: string) => void) | null = null
 let openAppHandler: (() => void) | null = null
+let scaleHandler: ((scale: number) => void) | null = null
 
 function currentPayload(): PetOverlayStatePayload {
   return {
@@ -173,8 +188,10 @@ export function popOutPet(petRect: PetOverlayBounds): void {
     return
   }
 
-  const width = Math.max(OVERLAY_MIN_W, Math.round(petRect.width + OVERLAY_PAD_X))
-  const height = Math.max(OVERLAY_MIN_H, Math.round(petRect.height + OVERLAY_PAD_Y))
+  // Size the window off the pet's scale (not the measured rect, which includes
+  // the shadow) so it matches the live resize math exactly — no jump on open.
+  const pet = $petInfo.get()
+  const { width, height } = overlayWindowSize(pet.frameW ?? 192, pet.frameH ?? 208, pet.scale ?? 0.33)
   const x = Math.round(petRect.x - (width - petRect.width) / 2)
   const y = Math.round(petRect.y - (height - petRect.height) / 2)
 
@@ -223,6 +240,11 @@ export function setPetOverlayOpenAppHandler(fn: (() => void) | null): void {
   openAppHandler = fn
 }
 
+/** Register the handler that persists a scale resized via the overlay's Alt+wheel gesture. */
+export function setPetOverlayScaleHandler(fn: ((scale: number) => void) | null): void {
+  scaleHandler = fn
+}
+
 /**
  * Wire the overlay→renderer control channel once. Returns a disposer. Idempotent
  * — a second call while already wired is a no-op.
@@ -245,6 +267,11 @@ export function initPetOverlayBridge(): () => void {
     } else if (payload?.type === 'bounds' && payload.bounds) {
       // The user dragged the overlay to a new desktop spot — remember it.
       saveBounds(payload.bounds)
+    } else if (payload?.type === 'scale' && typeof payload.scale === 'number') {
+      // The user resized the popped-out pet (Alt+wheel) — persist it through
+      // the main renderer's gateway; the new scale rides $petInfo back to the
+      // overlay on the next push, keeping both surfaces in sync.
+      scaleHandler?.(payload.scale)
     } else if (payload?.type === 'open-app') {
       // Mail icon: surface the app on the most recent thread (main.cjs already
       // focused the window before forwarding this) and mark it read.