Marvel Universe Roleplay
Mutants, or homo superior, are a variant of humans born with the X-gene in their DNA. They are considered by some to be evolved humans, and their special gene gives them a huge array of powers.
Some find themselves discovered by the Professor Charles Xavier, a powerful mutant telepath, and brought to his academy where mutants can find safe refuge and education. This is good, because mutants are generally hated by humanity for being an entire species of not only freaks, but powerful freaks.
Others either wander on their own, or end up fighting against regular humans, like the infamous Magneto.