BLACKBIRD
Blackbird first appeared as Jackdaw in the Incredible Hulk#274. Right now, her true name is unknown, but she is both a mercenary and a spy who used to work for the Leader until he abandoned her after she tried to help the Hulk and the Avengers foil one of his schemes. She later went to work for Superia as one of her main lackies beginning in Captain America#388, where she renamed herself Blackbird.

Blackbird possesses a lightly armored suit with wings that enable her to fly at an undetermined speed. Her costume is equipped with twin grappling claws attached to cables that can ensnare an opponent and bind them up.
My first exposure to Blackbird was in Captain America#388, where she teamed up with Moonstone to try and capture Captain America, the mercenary Paladin, and also John Jameson, all of whom had been left floating in a raft amid the Mid-Atlantic after being attacked by MODAM, another one of Superia's agents.
After taking out Paladin with one of her grappling wires, Blackbird hung back and let Moonstone try and deal with Captain America. Shortly, after Captain America freed Paladin from Blackbird's grappling wire, Paladin took out Moonstone with one well-aimed shot. Blackbird attempted to save Moonstone from drowning, but Captain America grabbed a hold of her ankles, causing Blackbird to take off into the air. She tried to shake off the good Captain but to no avail. She prepared to use her last grabbling claw against Cap, as shown in the picture above, but Cap ended up outmaneuvering her and choked her until she passed out from lack of air.

The next time we saw Blackbird was in Captain America#411-413, where she attended an AIM Weapons Expo with her boss, Superia, and her fellow body-guards, Iron Maiden and Snapdragon. After Superia murdered Brannex, the CEO of AIM, so that she could take over his organization and use its profits to further her plans for world domination, AIM's prime agent MODAM, who no longer worked for Superia, attacked Superia. Blackbird and Iron Maiden attempted to assist Superia, but they were briefly waylaid by a force field. When MODAM attempted to flee the scene with a captive Superia in tow, Blackbird pursued them, but MODAM rendered Blackbird unconscious with a laser blast. It should be noted that Brannex had survived Superia's murder attempt because he was revealed to be not human but an Adaptoid.

Since then, Blackbird has never been seen again. Superia was killed later on by the Red Skull, so more than likely Blackbird has returned to her life as a mercenary for hire. I, for one, love this character, and I very much would like to see Blackbird make her triumphant return someday in a Marvel comic.
Blackbird's List of Appearances:

The Incredible Hulk#274-275
The Incredible Hulk#277-281
Incredible Hulk#283-284
Captain America#388-389
Captain America#411-413
Hosted by www.Geocities.ws

1