X-Men (1963) 19-A

"Lo! Now Shall Appear--The Mimic!"

After earning a vacation, the team goes out to enjoy the "normal" life but for Henry and Bobby its anything but normal as they run into a jealous "not quite" boyfriend of Henry's date. But this boyfriend is anything but normal either as Calvin Rankin is a mutant whose powers mimic those of any mutant he is around. He absorbs the powers of the X-Men and kidnaps Jean to lure the team to his secret hideout in an abandoned mine where he can use the power of the X-Men to recover a machine built by his late father that would cement the powers that he mimics. But Rankin's father did not create a machine to help keep his son's powers, but one to take them away as that's what happens..?

Origin and first appearance of the Mimic.