Toothgnasher and Toothgrinder are characters appearing in American comic books published by Marvel Comics. They are based on Tanngrisnir and Tanngnjóstr from Norse mythology. Thor usually relies on his hammer Mjölnir to fly. In situations where he must transport passengers or objects, Thor can summon Tanngrisnir and Tanngnjóstr, both also known as Toothgnasher and Toothgrinder, who arrive already harnessed to his chariot, and can be dismissed with equal ease.[153] The two goats were vital in a later Marvel Comics story; they believed a tale of danger to Odin and summoned reinforcements. They later made sure various Asgardian children were safe when an invading army threatened.[154]