Asriel Dreemurr is the biological child of Toriel
and Asgore and the adoptive brother of the first human.
He serves as the final boss of the True Pacifist Route.
Similar to Toriel and Asgore, Asriel has long ears, a snout, and visible fangs.
In his initial form, he wears a green, long-sleeved shirt with yellow stripes
and black pants, similar to the First Human's clothing. He also has a small patch
of fur on his head and lacks horns.
Before his death, Asriel was a docile, boring, and loving child. He cared
for the First Human as a sibling, and he trusted them when they came up with a
plan to escape the Underground.
After Alphys resurrects Asriel without a SOUL as Flowey, he becomes incapable of
feeling love. This makes him bored and resentful.
After temporarily regaining his compassion, he apologizes for his actions
Much like his father, Asgore, he speaks using southern slang.