X-Men Impostors

Before Blob joined numerous supervillains in pretending to be Defenders, he pulled off a similar stunt in X-Men #20 (reprinted in #71). During that earlier crime spree, Blob and fellow evil mutant Unus disguised themselves in costumes matching those of the original X-Men. The ruse exacerbated an undercurrent that followed the X-Men and would carry through to the New Defenders. To much of the general public, all mutants were a menace, with little distinction made between mutant heroes and mutant villains. X-Men #20 also provided an important piece of background about Professor X, telling how he had lost the use of his legs when facing an evil extraterrestrial called Lucifer.

As a sign of their achievements, the original X-Men began wearing individualized costumes in #39. The original costume style returned as a student uniform when Kitty Pryde joined the X-Men in #139; the New Mutants would would wear a variation of this original uniform as well.