my vote is the african knife fish. mine does the most stupid things i have ever seen a fish do, he will go down in my sand, turn on his side and swim like that "scratching" his side and he does this for the entire length of the tank. he also swims very slow and out of now where he will "jump" so that he is vertical in the water with his head down and tail up, strange part is he does it so fast you cant even see him do it. lol, he also thinks he is now a cichlid as he started eating cichlid sticks and eats them in the same manner as my jd. he takes it in longways and plays with it.