A laid-back and lazy but sharp-witted skeleton from Snowdin.

A warm and kind goat who serves as the Guardian of the Ruins.

A pure-hearted and confident skeleton from Snowdin.

The passionate, brave, and justice-driven fish-warrior of Waterfall. (Transforms into Undyne the Undying only on the Genocide Route.)

The genius scientist of the Hotland Lab with a timid, otaku personality.

The gentle, kind, and responsible goat king of the Royal Palace.

A flower who appears playful and kind on the outside but is extremely cruel within.

(Appears only in the True Pacifist Route.)

(Appears only in the Neutral Route.)

A human girl possessing Determination.