Human

Humans were a race that lived on the surface of the Earth, beyond the barrier on Mount Ebott.

Overview
Humans had formerly ruled over the Earth peacefully with monsters, but that peace was broken when a war had broken out between both races. After what was said to be a long battle, the humans claimed their victory and banished all monsters beneath Mount Ebott with magic. Humans had lived on the surface ever since they won the war. Eight humans were known to have fallen into the Underground: the First Human, Frisk, and the six humans whose SOULs were stored in New Home. Humans as a whole were seen as evil by monsters, especially since Asgore declared to kill any human who entered the Underground, yet most monsters did not know what a human looked like. The job of patrolling for humans was entrusted to the Royal Guard. Humans indirectly affected the monsters' society. Waste from human society flowed through rivers into the Garbage Dump. This waste had influenced monsters' technology and media; for example, anime and manga remained one curiosity to monsters. This waste had also distorted monsters' perception of human society, such as Undyne believing anime to be human history. Acculturation of human customs occurred as well, such as Mettaton's interest of keeping his resort's standards similar to those of humans.

Physiology
Human bodies are composed of physical matter, as opposed to monsters' more magical bodies. Because of this, human SOULs are not attuned to their bodies like monsters are. This trait allows their SOULs to persist after death. The physicality of human bodies also allows humans to carry higher concentrations of determination than a monster. It also appeared that they were once capable of magic, as they sealed the monsters underground with a magic spell following the war.