The Other Mother is responsible for every disappeared character in any media
The Cracks in Time are responsible for the disappearances.
There is a pocket dimension......that consists of one town. It holds all of the characters that suffer from Chuck Cunningham Syndrome. It has a hospital for the ones who left sick, an asylum for the mentally insane, a giant entertainment zone for the children- it has everything.
The missing characters go into a Lotus Eater Machine.