LMDs
If you haven’t seen the Marvel TV series Agents of S.H.I.E.L.D. then you are missing out. Following a team pulled together by Agent Phi Coulson after he returns from the dead at the end of The Avengers, it pulls together many threads from the MCU and hosts a swathe of loveable and fascinating characters.
One of the plotlines, taken from the Iron Man comics, concerns Life Model Decoys, robots who can be programmed to pretend to be anyone. Aida, one of these LMD’s is probably the best villain in the series. In The Avengers, we hear Tony Stark mention LMD’s to get out of a meeting with Coulson, as a nice little crossover nod.