Virus (Supernoobs)

This virus like any is an extraterrestrial symbiotic organism but that has been created and developed by a mysterious source to infect the entire galaxy as it mutates whatever host it comes to possessing, turning them into monstrous beasts.

Biology
The virus is a small entity that is send straight to numerous planets including Earth and infect who or whatever it comes into contact with. Once infected, the victim instantly changes, becoming corrupted and the only cure is for the virus itself to be remove for its own host and destroyed which immediately reverses the mutation.