A native of the Dirt Seas, where swimming and bathing was routinely done not in water, but in dirt, the dirt shark Terrafin became a Skylander after crossing paths with Master Eon, a human Portal Master who was impressed with Terrafin's fighting abilities. At first reluctant to leave his home planet, Terrafin eventually was persuaded to join and train as a Skylander.
As a Skylander, Terrafin is notable for his vast array of fighting skills, especially in close combat, where he makes the most of his quickness. He can also burrow underground, then surprising his opponents by literally propelling himself into the air before delivering a crushing bellyflop, ending the skirmish.
Brutally blunt and not one to waste time talking, Terrafin has few friends, and apparently that's the way he likes it.