There was a movie and a grandson has to find a blue skull that was his grandfathers but it was stolen. He went through rooms of his grandfathers house to look for it. There was a dinosaur room, and an old cowboy trying to find and steal it. They had a green pet caterpillar too. What is it called?

Isn't this Indiana Jones? Kingdom of the Crystal Skull?

It's House II: The Second Story. Goofy fun.