Kani Goalkeeper is a movie about a crab who serves as a soccer team's goalie. No, really! Scroll down to watch the hilarious trailer for it.
This movie isn't a complete oddity. It's one of multiple films in a Japanese film genre that may be called "sea life sport movies," which is, as you might guess, about sea creatures playing human sports.
This genre is one of ten bizarre ones described by Alison Nastasi of Flavorwire. You can see the rest at the link.