Spider-Man: The Animated Series 1x13

An international spy and hitman known as the Chameleon plans to assassinate two major diplomats on the brink of signing the peace proposal of the century. S.H.I.E.L.D. director Nick Fury solicits J. Jonah Jameson's assistance in an effort to prevent the "human shape-shifter" from derailing the proposal signing. But only Spider-Man with his super keen "spider-sense" can discern who is really whom and stop the criminal before it's too late.