This is a Flash animation created in Adobe Flash CS4 primarily via ActionScript 3.0. Each part of the fish is a movie clip with an associated AS3 class.
Click on animation to give it focus. Then move the fish using the arrow keys. Click on the fish to release bubbles.
Notice the fin and tail movements which are simulated by different techniques. Also note that the fish is watching you.
Flash
Flash CS4, Animation, Image, as3, Movieclip