Fan Casting Undertale: The Movie

Undertale is set in the Underground, a realm where monsters were banished after war broke out with humans. The Underground is sealed from the surface by a magic barrier with a singular gap at Mount Ebott.[15] A human child falls into the Underground from Mount Ebott and encounters Flowey, a sentient flower who teaches the player the game's mechanics and lies about "LV", or "LOVE", in an attempt to kill them. The human is rescued by Toriel, a motherly goat-like monster, who teaches them how to survive conflict in the Underground without killing. She intends to adopt the human, wanting to protect them from Asgore, the king of the Underground.