Kani Base is a crab chojin.
In the 20th Chojin Olympics preliminaries, the fighters had to participate in a game of Rock-paper-scissors. Kinnikuman took on Kani Base who because he had pincers for hands could only choose scissors, Kinnikuman chose rock and beat him. Before the 21st Olympics he had his pincers changed to hands, and lost again when Kinnikuman chose scissors. Friends with Kinkotsuman and Iwao.
Kani Base is first seen as the Italian representative during the 20th Chojin Olympics Arc.  He is accidentally elbowed by Kinnikuman in the face, which causes a fight to break out, but a rock-paper-scissor match is declared as a means to see who will qualify for the competition. Kani Base is angry at such a game being a major deciding a factor, and this is made worse by how his pincers only form 'rock' and so Kinnikuman beats him with 'paper'. He is not seen again until the next Olympics arc. 
During the 21st Chojin Olympics: The Big Fight arc, we see that Kani Base has applied again to be a contestant, as he seeks to finally prove his worth over Kinnikuman.  He reveals that he was able to change his pincer-hands into fingered-hands with plastic surgery, so Kinnikuman's tactic of using "rock" in the rock-paper-scissor game is ineffective, but Kinnikuman uses 'scissors' instead, as now all he can do is 'paper'. He thus loses once more. 
(More to Come)
- He was named Buster Crabb in Ultimate Muscle
- Submitted by: Soutarou Minamoto from the Yamaguchi Prefecture, Japan