my two dogs, Hazel and Zeke, howl whenever the fire whistle goes off in town, and don't stop until the whistle stops (or until they see you watching them and get embarassed).
my cat Dirtball likes to eat peas. also, if you have been petting him for a bit, then stop and try to walk away, he gets mad and runs after you and tries to grab onto your leg.
and my betta fish, Mr. Wiggles, gets real excited everytime someone comes near his tank, and proceeds to zoom around and wiggle like crazy.