Rested Zzz brings the native resting animation to a standalone overlay.

I recently switched to EllesmereUI and will never look back.  But I wanted the animated "Zzz" when resting.  I remembered having this same "issue" a while back with a different Unit Frame addon so I just made what I "needed"

Place the animation beside your portrait, above your health bar, or wherever you prefer. The addon reads the client’s native resting artwork and animation settings.

When locked, mouse clicks pass through to your player frame.

Type /rzzz to show the preview. Drag to move, mouse-wheel scroll to resize, and right-click to lock.

Additional commands:
/rzzz: Show the preview. Drag to move, scroll to resize, and right-click to lock.
/rzzz lock: Hide the preview.
/rzzz scale 1: Set the size. Use 1 for default, or a value from 0.25 to 4.
/rzzz reset: Restore default size and center the preview.
/rzzz status: Display animation detection and game client details for troubleshooting.
/rzzz retry: Try detecting the native resting animation again in the event it hangs up.

This addon is NOT linked to a unit frame, so if you move your player frame, you'll have to adjust this addon.

DISCLAIMER:
**I used Codex to help write the addon’s code. I directed the features/design and have tested the addon in-game. "Rested Zzz" does not use AI while you play.**