Have you seen the roomguard version of the Sulley character? It's a big, fluffy (not plastic) version of Sulley mounted on a plastic base. You push a button at the front and it activates a motion sensor. When motion is detected, Sulley roars (loudly) and then gives some funny one-liner.
We gave one of these to my wife's neice for Christmas. Being a bit devious, she set it up to aim at the top of the staircase before she went to bed New Year's Eve. At 1:00am, a guest walked up the pitch-dark stairs to get his coat.......
He said to my brother-in-law, "I want to thank you for almost making me pee in my pants."
Acme