Big in Japan: Crustacean Deathmatches
You’ve got to hand it to the Japanese for more than just the weird stuff; they also deserve credit for originality as well.
Meet Crustacean Deathmatches, a show in Japan that puts primarily crustaceans into a small fish tank then films the fight that inevitably follows due to neither creature having an awful lot of room to move.
Four clips as follows. The highlight is the introduction of an Octopus into a fight against the star of the show, a creature that looks like a Morton Bay bug in the 4th clip.