Rodriguez

Rodriguez is a Japanese rhinoceros beetle who is the pet of Mugen. The beetle is a contestant in beetle sumo wrestling, and is one of the few non-human characters in the show.

History
Rodriguez is first seen in a gambling den fighting another male beetle on a log. Mugen cheers on the beetle to win but he is pulled back for going too close to the beetle, and the opposing beetle uses its horn to flip over Rodriguez, causing him to lose the match.

Later at night, Mugen ties a rope around Rodriguez's horn with a small rock at the end of the rope. The beetle is supposed to pull the rock so that his strength somehow increases. Fuu walks in and sees this, and Mugen says he quit his last job since Rodriguez will make them plenty of money in beetle fighting. She says the plan is asinine, but Mugen disagrees.

When Mugen brings Rodriguez to the den for another match, Fuu tags along and thinks the whole plan is ridiculous. As she mutters to herself, Rodriguez clashes with the beetle and is able to flip over the opposing beetle, winning Mugen and Fuu lots of money. This is the last time the audience sees Rodriguez.

Trivia

 * Unlike female Japanese rhinoceros beetles, male beetles like Rodriguez have a large Y-shaped horn on their head.
 * In real life, beetle fighting (insect fighting) is a popular hobby in Japan.