Spider-Man And Peter Parker Are Split Into Two
Due to a lab accident caused by an attack by Taskmaster, Peter Parker is hit by an Isotope Genome Accelerator, and his persona Spider-man is physically separated from him. Now there’s both of them running around New York City.
I recall something similar happening to Bruce Banner and the Hulk? The two of them being separated and Bruce shutting himself in an island creating montrosities in a bid to get the Hulk back?