Another simple animation from The Professional Step-by-Step Guide to Cartooning by Ivan Hissey and Curtis Tappenden. This is about as simple as animating gets: one layer is the paper background, then there’s the puppy, minus its left ear, and finally the ear itself, pivoting up and down on an anchor point on the puppy’s head.
You convert the ear into a Symbol and the book mentions that in Flash you can store as many as 16,000 symbols in the library! Probably more now that Adobe has replaced Flash with Animate, but I intend to keep things as simple as possible. One Symbol is a start though.