Do you want to compare U.S.Agent with Viper? Discover the powers, weakness & weapons of U.S.Agent and Viper from U.S.Agent Biography and Viper Biography. Find out all about U.S.Agent and Viper.# Check out how is U.S.Agent unique and distinct from Viper. Discover their love interest, sidekicks, family tree and the movies and games list in which U.S.Agent and Viper have appeared. Find out everything about them here!