A humanoid creature, Wyrm possessed an unusually large frog-like head with a sprouting of what appeared to be worms on top, bright blue skin and a tentacle in place of his right leg. He wore a green jumpsuit of some kind with a large yellow collar.
Wyrm was one of three chaotic reality-manipulating creatures who were imprisoned in fifth-dimensional cells called Hypercubes by unknown means and scattered across the universe. He had vast cosmic powers, including the ability to grant others' wishes, although if three wishes were to be granted, then Wyrm would be freed from his captivity.
When the Teenage Mutant Ninja Turtles, along with Casey Jones and April O'Neil, investigated a derelict spacecraft, Casey got bored and wished for something interesting to happen. Unaware that the mysterious box he had just discovered was actually the Hypercube containing Wyrm, this wish was granted, and the group had to battle their way through a horde of Astro Zombies which appeared from nowhere.
Later, aboard the Ulixes, the robot Fugitoid informed the others of the cube's contents, and told them that if Wyrm was ever allowed to get free then he would destroy the whole of creation. A possessive Casey opened the Hypercube anyway and the travellers were confronted with Wyrm for the first time. He explained to them that they may make two more wishes, and told them the rules of wish-making, one of them being that no wish may harm Wyrm. Casey wished to know everything, and Wyrm granted this desire, showing him the secrets of the cosmos.
The Turtles and April decided to make their final wish one that counted, but Wyrm became impatient with them and they end up battling each other, although it quickly became apparent that the Turtles were no match for the alien, and that Wyrm was merely toying with them. During the battle, Raphael accidentally wished for a Wyrm-destroying laser cannon, and this materialised in his hands. The weapon was non-functional, however, as it broke Wyrm's rule about wishes harming him.
Unfortunately, the result of this was that Raphael's wish set Wyrm free, and using his unfettered powers he went about destroying the galaxy. Casey, using his now-limitless intellect, tricked Wyrm into believing that he desired an alliance; Wyrm however, demanded that he kill the Turtles as proof of his sincerity. Casey agreed, but stated that he required another wish in order to wipe them out for good. Wyrm granted this request, and Casey wished that he had never found the Hypercube in the first place; Wyrm was bound by his own rules, and forced to honour the wish, returning himself to captivity in the Hypercube and ending his threat to the universe.