When Peter Parker gets bit by a radioactive spider on a school field trip (don’t you hate when that happens?), he develops super strength, the ability to cling to any surface, and a spidey sense. At that point, he has no choice but to build web shooters for his wrists and call himself Spider-Man.
In the Marvel Universe, Deadpool (aka Wade Wilson) is a mentally unstable mercenary. He’s hugely popular with comic fans as the merc with a mouth, frequently breaking the fourth wall. In the Wolverine movie, Ryan Reynolds also portrayed something that kind of resembled Deadpool, I guess…?