Napstablook is a dour introvert with low self-esteem. Napstablook cries in battle, which may indicate some form of depression, anxiety or sorrow. Despite this, Napstablook is courteous to others and treats the protagonist as a guest when they visit Napstablook's home (even if attacked in the Neutral Route). They often employ self-deprecation and apologize for any inconveniences to be polite.