Board Thread:News and Announcements/@comment-4224349-20150219162914/@comment-25989704-20150324031933

Possible explanations.

1-Uncle Grandpa is actually a little loopy and all his crazyness is mostly imagination, pet cat, pet lizard, pizza stuck to his RV's wall. Implied there might be more to him in resolution.

2-A Gem monster breaks a hole in their dimension leading to or leading Uncle Grandpa to the Steven Universe world.

At any rate while I am skeptical about this crossover I actually kinda welcome some magic/paranormal stuff not coming from Gem related biz, It makes the world seem a little bigger.