Terraspin is a green turtle alien with eight holes in his shell. He also has large, flipper-like arms and stumpy legs. He also has retractable claws to use as fingers.
In Omniverse, Terraspin now has six holes instead of eight, has spots on his upper legs,toes and shoulders, and has a hectagonal body shape rather than circular. His skin is now green instead of a tan/brown. His feet have gained toes as well.
Terraspin's powers are aerokinetic, meaning that the basic element he controls and manipulates is air and wind. He can retract into his shell and blow very strong and powerful winds out of the holes on his front side. The black spots at the end of his flippers can extend into finger-like claws. He can fly by pulling into his shell and blowing air out to push himself along. When flying or creating wind, Terraspin retracts his head into his body, his fins become triangular and his legs combine into a similar triangular shape. He rotates with his shell staying static and suspended, like a wind turbine. As revealed in Map Of Infinity, his species is impervious to magic and mana. He can withdraw into his shell, which is hard enough to protect him from most attacks. He can also spin at high speeds to throw things around. He can suck in things like a vacuum to pull things towards him. Terraspin can swim by blowing out the air from his port holes to push him along through water. He also possesses enhanced strength.
Terraspin's name is a mix of terrapin, which is a turtle or tortoise, as well as spin, referencing his ability to do such.
In Absolute Power: Part 1, Gwen had used a spell that had slowed Terraspin down, despite that he is supposed to be immune to mana-based attacks. Dwayne stated that "Terraspin wasn't using his powers, but Aggregor was". This means that his mana immunity can be used or not.
In Cosmic Destruction, you can see Terraspin's eyes peeking out of his shell while he's hovering.
Terraspin does not say anything except his name until Absolute Power: Part 1.