Biting is a physical attack used several times in the Dragon Ball series.
Goku resorts to biting several times in the series, first biting King Piccolo's thumb (managing to draw blood in the process), then biting Frieza to escape his Tail Attack, and finally biting Kid Buu's head after Kid Buu bites his arm. In Dragon Ball Super, Goku bit the tails of Beerus and Golden Frieza while fighting them. He also bites Whis during a sparring session. In Dragon Ball GT, he also bites a rock in pain while Old Kai is trying to pull out his tail.