Toonworld

When new universes form, they can't from nothing. They pull from other universes to get themselves started, taking concepts to build their reality, and creatures to inhabit them.

People began vanishing from our world, sometimes literally falling through the cracks as they found themselves in a cartoon world. Their bodies changed to match whatever new setting they found themselves in. For this soul, they found themselves dropping into a sewer to become the new resident gator.