Viper
AKA: Madame Hydra. Mrs. Smith. Chthon once called her "Meriem," and she called herself Meriem Drew, but that storyline has pretty much been disbarred from continuity, darn it.
First appearance: Captain America 110
Favorite quote: "I hate bad news." (Captain America 281, after ventilating the unfortunate subordinate who made the mistake of telling her what she didn't want to hear.)
Team affiliation: Once one of the highest ranking of HYDRA's covert agents, Madame Hydra annexed the New York branch of the organization for herself. When that fell through, she destroyed the original Viper. Taking his code name and his snake-themed group of villains called the Serpent Squad, Viper briefly wore the dreaded Serpent Crown. She had a second stint with snake-themed bad guys when she headed the Serpent Society. Viper is a frequent partner of the Silver Samurai, although their various criminal activities often take them in different directions. Her alliance with the Red Skull was contracted without the Silver Samurai's input. Her relationship with her parent organization of HYDRA remains strained, not in small part because her belief in ultimate chaos with total universal death and destruction clashes with HYDRA's goal of world domination -- after all, for world domination to work, something has to be left to dominate...
Abilities: Viper is a superb hand-to-hand combatant, once fighting the Black Widow to a stand still. Unfortunately it was on a blimp, where Viper had more problems with the wind currents than the Widow. In addition, she has the considerable and inspired armaments of HYDRA at her command. And, as her loyal Silver Samurai once said after she wondered why he bothered rescuing her, "You have exceptional skills as a terrorist, a strategist, a leader." Just the sort of person subversive organizations want!
Favorite storyline: The weirdness that was Spider-Woman 42-44. Recognizing Jessica Drew as a younger version of herself, Viper remembered the child she left in the care of the High Evolutionary years earlier, leading to a complex series of revelations and some decidedly odd powers for Viper involving that empty eye socket she's always hiding under her hair.
Least favorite storyline: Oh, you have to ask? Naturally if Spider-Woman 42-44 was my favorite, then my least favorite involved the two pages in Captain America 281 where Viper realized -- hey, it was all just a magic-induced dream! One of those previous-story-blow-offs that make fans wonder why the heck they bother reading comic books at all ...