Cosmo was a
Soviet space dog during the 1960s and was launched into Earth's orbit by the
Soviet space program as part of an experiment. Cosmo was lost in space and mutated by exposure to cosmic rays, gaining psychic powers. Eventually, Cosmo landed on
Knowhere, a city located within the severed head of a giant
Celestial, and became Knowhere's security chief.
Nova meets Cosmo shortly after encountering Suspensor, who he kills in self-defense. Cosmo and Nova are ambushed by a group of zombies, including the surviving members of Suspensor's former team, the Luminals. The two determine that
Abyss was responsible and seal him away. Peter Quill's original Guardians of the Galaxy team operated out of Knowhere for some time, thus dragging Cosmo into many of their exploits. During one such adventure, Cosmo and the Guardians bounce around the time stream in an attempt to stop the Fault, a tear in the universe, from eliminating all of reality. During this adventure, Cosmo is de-aged into a puppy. During
The Thanos Imperative storyline, the corrupted beings of the Cancerverse invade
Earth-616 through the Fault. The Guardians of the Galaxy allied with Thanos to stop
Mar-Vell. During the battle,
Phyla-Vell is killed and
Adam Warlock, Drax, and
Star-Lord are presumed dead. At Star-Lord's request, Cosmo gathers
Silver Surfer,
Gladiator,
Beta Ray Bill,
Quasar, and
Ronan the Accuser to protect the universe together. Cosmo is seen with several new Knowhere enforcement allies called the Knowhere Corps. They assist him in capturing a violence-loving gangster called Yotat. ==Powers and abilities==