Andrew "Andy" Maguire of earth-535 comes from a world where the Parker particles passed through Peter Parker and then struck Andy, imbuing him with Parker's spider powers.
Andy Maguire was an student at Midtown High, the same school Peter Parker attended, but unlike Parker, he was not a good student, who was completely ignored by everyone and his parents did not care of him too much.
One day during a demonstration at Horizon Labs, presented by Peter Parker, an accident similar to Parker's granted Andy some of Peter's powers.
Realising what he could do, Andy made a costume with a similar design to Pete Ross (spider boy). Taking the name spiderboy, Andy came across a mugging and acted quickly, saving the victim but seriously harming the criminal.
He was found by spiderman, spider girl and spider woman, who had all realised he had gained spider abilities after looking at a blood sample.
After investigating with Reed Richards, they come to the conclusion that Andy was stuck with his powers forever, and spider man was convinced to take Andy on as his sidekick.