Serpentor is a fictional character and a recurring antagonist from the G.I. Joe: A Real American Hero toyline, comic books, and animated series. Introduced in 1986, the character rules as Emperor over Cobra where most versions are depicted as a composite clone of history's greatest leaders. Serpentor serves as the primary antagonist of the second season of the original animated series.

G.I. Joe: A Real American Hero is a military-themed line of action figures and toys in Hasbro's G.I. Joe franchise. The toyline lasted from 1982 to 1994, producing well over 500 figures and 250 vehicles and playsets. The line reappeared in 1997 and has continued in one form or another to the present day. It was supported by two animated series as well as a major comic series published by Marvel Comics.