Several teams calling themselves the Lethal Legion have appeared over the years. The first was organized by Eric Williams, the Grim Reaper, to seek revenge on the Avengers for the apparent death of his brother, aka Wonder Man. Members included Swordsman, Power Man, Living Laser, and Man-Ape.
The second Lethal Legion was created by Count Nefaria to attack the Avengers, but he later turned against them and drained their powers to make himself superhumanly powerful. Members included Power Man, Living Laser and Whirlwind.
The third Lethal Legion was once again gathered by the Grim Reaper, including Ultron-12, Man-Ape, Nekra, Goliath III, and the Black Talon.
The fourth Lethal Legion was created by the Hell-Lord Satannish and his puppet the Hangman, using the resurrected shades of evil historical figures.
The fifth Lethal Legion was reorganized by the Grim Reaper to oppose Norman Osborn during the Dark Reign. Members included Nekra, Wonder Man, Absorbing Man, Grey Gargoyle, Tiger Shark and Mister Hyde.