- Ultimate Spider-Man
- The most well known example is, of course, Miles Morales. He was bitten by a genetically modified spider from Oscorp, and gained powers similar to those of Spider-Man. However, he refused to do anything with them, and continued with his life as always. Until Spider-Man was killed by the Sinister Six, and Miles felt guilty: if he had been there, he may had been able to help. He took a halloween Spider-Man costume and started fighting villains, but got a lot of What the Hell, Hero? for it: Peter Parker (his identity became public knowledge) was remembered as a hero, and someone taking his identity seemed in bad taste. He took his time to slowly earn the approval of everybody.
- Norman Osbourne gave some Oz to his son, Harry, so he could become a monster like him. It did not turn out well: he turned against Norman, Norman fought him to force him to obey, and inadvertently killed him.
- Peter Parker took a sample of the Venom project and used it on himself; he almost lost his mind and had to destroy it. Eddie Brock took the other sample, and became Venom. Some years later, Conrad Markus stole another sample from Roxxon and used it to become the new Venom.
- The Ultimates
- The Black Widow that we first saw was Natasha. In Ultimates 2 she turned to be a traitor, and was killed by Hawkeye. There was a new Black Widow some time later, Monica Chang, but she was actually the original Black Widow, thanks to retcon. And in All-New Ultimates Jessica Drew ditched the Spider-Woman persona, and became the third Black Widow.
- In a similar manner, it turns out that Bruce Banner is the second Hulk, Tyrone Cash was the first one. However, Cash stayed out of the whole superhuman arms race, and just used his power to have a luxury gangter life in a third world country. Gregory Stark also made a clone of Banner, capable to keep his intelligence while hulked out, he fought alongside the Ultimate Avengers as "Nerd Hulk".
- The Wasp was killed and eaten by Blob during Ultimatum. Petra Laskov became the new Wasp for the Ultimate Avengers. However, it was only to have her revenge against Red Skull, and retired once that work was done.
- The government tried to do this with Captain America's son. It backfired horribly. The kid became a terrorist, disfigured his own face and became Red Skull.
- Captain Marvel died fighting against Galactus during the Hunger miniseries. Rick Jones took his powered armor and became the new Captain Marvel.
- Daredevil, Matt Murdock, died during Ultimatum. Stick took a new protegee and trained him as the new Daredevil, but they were captured and converted by vampires.
- Dr. Strange is a legacy character from the get-go. He's part of a heroic lineage, and his father vanished many years in the past. He studies hard to try to be at least a half-competent sorcerer.
Legacy Character / Ultimate Marvel