The Hulk [Bruce Banner] (introduction, origin]; Rick Jones (introduction); General Thunderbolt Ross (introduction); Betty Ross (introduction)
Scientist Bruce Banner saves a young boy from being killed by a nuclear blast but absorbs deadly amounts of gamma radiation which transforms him into a monster dubbed the Hulk; Bruce Banner is scientist by day, but transforms into the Hulk once the sun goes down.
Reprinted from The Incredible Hulk #1 (Marvel, 1962 Series)(Chapters 1 and 2)
Spider-Man [Peter Parker] (introduction, origin); Ben Parker (introduction); Crusher Hogan; Flash Thompson (introduction); Liz Allen (introduction); May Parker (introduction); the Burglar
Peter Parker is bitten by a radioactive spider and gains the abilites of a spider. When he fails to stop a burglar who runs past him his uncle his killed as a result. He therefore swears never to shirk his responsibility again.
Reprinted from Amazing Fantasy #15 (Marvel, 1962 series)(Chapter 1 only)