Guessing Game

Here's the scene. Husband is trying to "guess" the themes of all 5 of Little Man's birthday parties.

Husband: "Ok, Little Man. There was John Deer, Thomas the train, Kung Fu Panda, Transformers and one more that I can't remember..." 

Little Man: "Try really hard Dad. You can do it!" 

Husband: "I can't remember, Little Man." 

Little Man:"Ok, Dad. I'll give you a hint. It starts with a B and ends with -atman."