Warning: contains spoilers for Ben Reilly: Spider-Man #4!
Out of all the Spider-Man clones that exist in the Marvel Universe, his most powerful has a unique ability among the others - and makes a certain famous blue shapeshifter in the X-Men rather obsolete. Peter Parker has legendarily poor luck in life, and that often manifests in the form of various clones who attack him one by one. One of those clones is the dreaded Spidercide - and in Ben Reilly: Spider-Man #4, he reveals one of his greatest abilities that can cause any Peter Parker variant to think twice before attacking.
Ben Reilly, Spider-Man's most famous clone, was created by a man named Miles Warren, otherwise known as the Jackal. Though he appeared to die in his original storyline in the 70s, Reilly reappeared in the 90s as part of the ill-fated Clone Saga. When the story, initially planned to last 6 months, was extended by Marvel editorial to two years, the creative team stuffed the story with multiple plot twists, new characters, and plenty of additional clones. One clone, named Spidercide, loathed Warren as much as the rest of his creations, and had a plan to bring Ben Reilly to his side.
In Ben Reilly: Spider-Man #4, written by J.M. DeMatteis with art by David Baldeón, Spidercide attacks Ben Reilly and brings him to a secure location, disguised as an ordinary home. There, Spidercide reveals he can not only change his shape, but he can seemingly break off pieces of himself and control them independently. He demonstrates this ability by manifesting all the people from Ben Reilly/Peter Parker's life: Gwen Stacy, Aunt May, and even Uncle Ben. Spidercide can even manipulate nearby minds - meaning there's a good chance he can use Reilly's own memories to shapeshift into his friends and even family members.
This shapeshifting ability is astounding, and leagues ahead of the other Marvel premiere shapeshifter Mystique. The X-Men shapeshifter can take any form, but she has limits: she can't radically alter her mass and can only take humanoid shapes, and she can only impersonate one person at a time. Spidercide, by contrast, can shapeshift into an entire group of characters at once. He can not only become any one person, but any team - including, perhaps, the X-Men, the Avengers, and beyond (he just can't replicate their powers, but Mystique has the same restriction).
While Mystique is used often in Marvel stories, Spidercide is rarely seen. He does have a spiritual successor in the form of Miles Morales' adoptive brother Shift (also a clone), but he cannot mimic others like Spidercide. This Spider-Man clone has tremendous potential to be one of the most feared foes in Marvel Comics, and can even eclipse Mystique when it comes to shapeshifting abilities.
Ben Reilly: Spider-Man #4 is available now from Marvel Comics, and fans can see the Spider-Man shapeshifter for themselves in all of his multiplying glory.