2001 animated short
Plot: A kitty saves half of his (her?) sister's soul and then accompanies her on a surreal journey.
At a little over 30 minutes, this is one magical journey. The imagery's a delicious blend of Hello Kitty, Salvador Dali, Bill Plympton, and Disney makes this hallucinatory but grotesquely lovely. You won't know what's going on exactly, but that matters about as much as it would if you were dreaming. Indeed, this moves along about as dreamily as 30 minutes of movie can move. In this animated purgatorial landscape, there's quite a bit of dismemberment, lots of blood, a guy preparing soup while wearing a dominatrix outfit, and even a little self-cannibalism. There's a character who might be God, but he doesn't seem to care much about anything but himself. I think there's meaning behind it all even if all the pieces are way too squishy to actually fit together.
This is recommended to people who understand that animation should really take advantage of its ability to break any rules and go anywhere. This one does exactly that, and it does it for exactly the right amount of time. You should check this out.