The world has seen many strange variations on Peter Parker's Spider-Man. Whether it was the time he took the role of The Punisher or when Deadpool took over for him in Spidey's first-ever comics, the wall-crawler has undeniably been put through the wringer. But it's the events of the Changes arc that saw his greatest transformation yet, with Spider-Man turning into an actual spider and then that spider giving birth to Peter Parker. Yes, you read that right.
After being ensnared by a newly introduced villain called the Queen, in the pages of The Spectacular Spider-Man Vol 2 #16, Parker finds his body changing in strange and unusual ways, and it ain't puberty.
After capturing and restraining Spidey, the Queen plants a loving kiss on the unwilling hero and even after their encounter ends, Parker still feels a weird connection to the mind-controlling Queen. It turns out that their embrace was more than a kiss, the Queen had actually injected Spider-Man with some sort of mutagen and when Mary Jane finds him at their apartment, the transformation has already begun, with Peter now sporting two additional eyes.
Attending a Star Trek-themed wedding at MJ's insistence, Parker comes up with the kind of disguise only a genius like him could conceive of - a pair of sunglasses. Feeling more changes coming along, Peter flees the wedding, with MJ dismissing it away to the guests as him having irritable bowel syndrome. Spider-Man is unable to control his thoughts as he swings through the city, seemingly still under the Queen's control. After fighting it as hard as he can, four new limbs erupt from Spider-Man's torso, while he screams in agony through a newly fanged mouth.
It's not long before Peter is a full-on, towering arachnid, now totally under the Queen's mind control in her subterranean lair. And as if Peter Parker's body hasn't already been through enough, things get even weirder when it's revealed that Spider-Peter is now also, somehow, pregnant. With his new eight-legged body unable to handle the stress it's been put through, he ends up abruptly keeling over, leaving the Queen devastated over the loss of her new pet. While spider Peter Parker is dead, it turns out his unborn baby isn't, and soon bursting out of the spider's corpse is... Peter Parker?
No further explanation is really given. A fully grown, naked Parker erupts from the husk of the spider that just moments ago was Parker. He retains all of his memories and strengths, not only that but now he can shoot webs directly from his wrists, eliminating any need for his traditional web-shooters. After rallying and defeating the Queen, Parker returns home to MJ, whereupon he simply explains away the webs shooting out of his wrists by saying, "I've made a couple changes."
Spider-Man's Changes storyline ran for four issues in 2004, which, incidentally, was not too long after the blockbuster success of Sam Raimi's first Spidey flick. With the movie being so popular, many speculate this was just a way to retcon the movie's organic web-shooters into the books. But there had to have been a less gross way of going about that. Either way, the whole ordeal must make for a confusing Father's Day at the Parker household.