Joined the team in Avengers #16 (1965)
Though technically a member of the Brotherhood of Evil Mutants, Quicksilver debuted in X-Men #4 (1964) alongside twin sister Scarlet Witch. Quick-tempered and compulsive, the cunning quickster had many a tussle with Xavier’s crew, from full-on combat to uneasy alliances
when facing biological father Magneto. But the villainy mantle didn’t quite fit Quicksilver, who emigrated back to Europe and reformed his destructive ways; occasionally lending his talents to the X-Men and spinoff project X-Factor.
The speed demon’s most notable hero gig, however, would arrive when Iron Man enlisted both him and Scarlet to join The Avengers in 1965. Retaining his rebellious edge, Quicksilver would prove to be the maverick of the team’s second generation; alongside his sister, Hawkeye and leader Captain America. The tenure was brief, but being that the character proved crucial in the beginnings of both iconic teams, he deserves his status as a double member. Luckily for him, movie studios seem to think so too.