Flag. Bird looks around. Click "fly" and bird will take off within a few seconds, flying until you click "land." Up and down arrows work too. The aim was to create smooth transitions between bird actions, yet responsive to your commands.
Used blender to render bird animation frames: one for standing looking around, one for taking off, one for flying, one for landing. Scratch code connects these smoothly using "repeat until" and broadcasts. Bird is on turbosquid. Pull those into blender, make any changes you like, then render bird with transparent background into several png frames.