Nasal mucus, produced in the nose by mucous membranes. The primary purpose of nasal mucus is to protect the body from harmful agents that might enter and infect a person, and to keep the skin inside the nostrils from drying out.

Snot typically isn't visible, because it doesn't flow out of the nose unless it is irritated, such as by an allergic_reaction, or if the character is ill. Snot can also be the result of excessive crying.