He first appears in Episode 1. Biff is a recurring character in the series and had the alter ability "NR Hammer," which creates a large mecha that, predictably enough, has a gigantic hammer for a right arm.

Spoiler

Later on, he gets captured and his abilities are refined immensely. He's also completely brainwashed in the process, to the point that his vocabulary becomes limited to "hammer" and all he can do is take orders. He eventually breaks free just before dying, recollecting his name as he falls to his death.

from wikipedia