Gets sinister at the end.
Wow. I was not expecting the dark turn at the end.
It's about a little boy and his dad, and no matter what his dad tells him, or shows him, he says “Whatever.” There's a tall giraffe, a small butterfly, curly trumpet, bouncy castle, train, and they fly to the edge of outer space. At the end, it's clear that his dad's getting really fed up by this, and shows him a tiger, and the kid says, “Whatever.” And the tiger eats the kid, and then the kid talks from inside the tiger like things do in fairy tales. “Dad, I'm still in here, you know.” And the dad says, “Whatever.”
I'm not sure what possessed the father to try to scare his son with a tiger, and to actually let the father eat his child. I'm also not sure why the father doesn't care that the tiger's eaten his child. I guess it's saying that the father is so fed up with his son being nonchalant that he has stopped caring about his child's safety.
If you look at it from an adult standpoint, it is funny in the same way as “Go the F--- to Sleep”, where it's funny because it's not something you would read to your kids.