Revealing mistake: When the Chairman is watching the TV screen where Damien Drake is being interrogated, the man steps in front of the screen and says "he's about to crack," then he walks backwards as if being pulled, but you can tell the moment Damien puts his legs around him, after several steps. So what pulled him back?
Revealing mistake: Throughout the movie, in Steve Martin's close-ups, you can see the line where his wig is.
Revealing mistake: In Africa, DJ and his group ride with Tweety and Sylvester an obviously Indian elephant (much smaller than the African one).
Revealing mistake: In the scene where the ACME Chairman turns on the screen to show Damien Drake tied up, you can see he has no remote in his hands and is just miming the action.
Answer: It's the alien from "The Man from Planet X".