diff --git a/docs/chat-chain-changes/2026-11-05-thinking-avatar.md b/docs/chat-chain-changes/2026-11-05-thinking-avatar.md
new file mode 100644
index 0000000..6004fbf
--- /dev/null
+++ b/docs/chat-chain-changes/2026-11-05-thinking-avatar.md
@@ -0,0 +1,9 @@
+---
+date: 2026-11-05
+pr: pending
+feature: Animated application logo while thinking
+impact: The thinking indicator uses the application logo with a gentle animation, disabled when reduced motion is requested. Chat behavior is unchanged.
+---
+
+The thinking indicator no longer uses the old character GIF. The new animation
+is applied to the existing application logo without changing chat events.
diff --git a/packages/client/src/components/hermes/chat/MessageList.vue b/packages/client/src/components/hermes/chat/MessageList.vue
index 4a55d50..98be76c 100644
--- a/packages/client/src/components/hermes/chat/MessageList.vue
+++ b/packages/client/src/components/hermes/chat/MessageList.vue
@@ -21,7 +21,6 @@ import VirtualMessageList from "./VirtualMessageList.vue";
 import MessageItem from "./MessageItem.vue";
 import { groupRunMessages } from "./groupRunMessages";
 import { LIVE_CHAT_MAX_LOADED_MESSAGES, useChatStore, type Message } from "@/stores/hermes/chat";
-import thinkingImage from "@/assets/thinking.gif";
 import { useToolTraceVisibility } from "@/composables/useToolTraceVisibility";
 
 const chatStore = useChatStore();
@@ -527,7 +526,7 @@ defineExpose({
         <div v-if="isThinkingIndicatorVisible" class="streaming-indicator">
           <div class="thinking-status">
             <img
-              :src="thinkingImage"
+              src="/app-logo.png"
               alt=""
               aria-hidden="true"
               class="thinking-avatar"
@@ -1479,10 +1478,19 @@ defineExpose({
 .thinking-avatar {
   width: 40px;
   height: 40px;
-  border-radius: $radius-md;
+  border-radius: 50%;
   object-fit: cover;
   flex-shrink: 0;
-  filter: brightness(1.18) contrast(1.08) saturate(1.08);
+  animation: thinking-avatar-breathe 2.4s ease-in-out infinite;
+}
+
+@keyframes thinking-avatar-breathe {
+  0%, 100% { transform: translateY(0) scale(1); filter: drop-shadow(0 0 2px rgba(var(--accent-primary-rgb), 0.12)); }
+  50% { transform: translateY(-2px) scale(1.06); filter: drop-shadow(0 0 7px rgba(var(--accent-primary-rgb), 0.4)); }
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .thinking-status .thinking-avatar, .thinking-status .thinking-status-label { animation: none; }
 }
 
 .thinking-status-copy {
diff --git a/tests/e2e/chat-rendering-smoke.spec.ts b/tests/e2e/chat-rendering-smoke.spec.ts
index bdfae9a..8749437 100644
--- a/tests/e2e/chat-rendering-smoke.spec.ts
+++ b/tests/e2e/chat-rendering-smoke.spec.ts
@@ -138,6 +138,25 @@ test('groups assistant output across tool calls until the run ends', async ({ pa
   await expect(page.locator('.run-end')).toHaveText('Run output ended')
 })
 
+test('animates the application logo while thinking and respects reduced motion', async ({ page }) => {
+  await authenticate(page, TEST_ACCESS_KEY, 'research')
+  await mockHermesApi(page)
+  await mockChatSocket(page)
+  await page.goto('/#/hermes/chat')
+  await sendChatMessage(page, 'think')
+  const { sessionId } = await waitForRunSessionId(page)
+  await page.evaluate((sid) => {
+    (window as any).__PW_CHAT_SOCKET__.latest.__trigger('run.started', { event: 'run.started', session_id: sid, run_id: 'thinking-logo' })
+  }, sessionId)
+  const avatar = page.locator('.thinking-avatar')
+  await expect(avatar).toBeVisible()
+  await expect(avatar).toHaveAttribute('src', '/app-logo.png')
+  await expect(avatar).toHaveCSS('animation-name', /^thinking-avatar-breathe/)
+  await page.emulateMedia({ reducedMotion: 'reduce' })
+  await expect(avatar).toHaveCSS('animation-name', 'none')
+  await expect(page.locator('.thinking-status-label')).toHaveCSS('animation-name', 'none')
+})
+
 test('opens the session model dialog and the session search from the chat header', async ({ page }) => {
   await authenticate(page, TEST_ACCESS_KEY, 'research')
   await mockHermesApi(page, { sessions: [sampleSession] })