Professor Kipple is the true main antagonist of Planet 51 and unlike General Grawl Professor Kipple does not redeem himself. He is also known the professors in Planet 51 hunting for the alien, putting him in the Observatory and capture Chuck Baker's brain to find out his invasion plans but at the end of the movie he was hiding while Base 9 was under alert until when he stopped hiding, the un-brained soldiers captured Professor Kipple for the brain operation of Kipple's brain.