Possed Horse From Berserk
Creature based Horse
theres only One spawned
near at the Hall of Death of Falkreath
also include
Hentai Creature(https://www.loverslab.com/files/file/5464-more-nasty-critters-special-edition/) addon mod
you can get this summon spell book using AIM SE(additemmenu) or additem console cheat