Hey! That movie’s funny!
when you’re on mushrooms…
Jack L. Chalker’s Midnight at the Well of Souls. Vardia Diplo goes through the Well and becomes a plant person. They reproduce by cloning. Eventually, she grows apart from her clone. It’s a subplot to the novel, not the main story.
Peter David (I think it was him) did this with Madrox/Multiple Man in one of the series of X-Factor. Madrox is a mutant with the power to make duplicates of himself, and while most of the time in his history they were just presented as identical clones, in this series, some of them go off and develop their own personalities, lives, agendas, essentially become new people.