Movie: Gremlins (1984)
Played by: Frank Welker
When playing Secret Santa, we are often tempted to buy our gift at antique shops in Chinatown. Whenever the compulsion to run down to Canal Street seizes upon us, though, we remember Gremlins.
Mogwai behave the same way kittens do. They are really cute, but if you don't train them right and keep them away from bright light, water, and food after midnight, they will make your life a living hell. The kitten will just rip up your loafers while the Gremlins spawned by your Mogwai will take over your town and shred it with decidedly non-seasonal cheer, but the principles are the same.
To recap: Lesson one, don't spoil your pets, and two, always choose the local Wal-Mart instead of shopping in some shady antique spot.