Harimao belongs to Yuji and wears a special mask.
Shiroi Senshi Yamato
He fights against a dog named Kumonryū in the circle tourament. Harimao defeats it by pushing its head against the other dogs and pushing it out of the ring, ending the match. He also fights against Yamato and is indeed strong until Miyashita interferes when Harimao is pushing against the smaller dog and insists that the dog fight without the mask. When the match is able to continue, Yamato manages to tear off Harimao's ear and the match is abandoned, resulting in Yamato being declared the winner.
See more pictures in Harimao/Gallery.