Muffet is a miniboss the protagonist encounters in Hotland. She runs a bake sale, being very angry at passers-by who do not purchase anything from it, even though buying something costs 9999 gold. Muffet is often portrayed as a greedy, stingy, intimidating and somehow hypocritical monster, although having a courteous and sweet way of speaking. Even so, she seems to have a quite malicious aspect on her personality whenever she is crossed, something that occasionally triggers her fight. During her battle, she also has a tendency to cite morbid or inappropriate things, such as commenting on the protagonist's possible fate in being used to make food.

Undertale
Undertale is set in the Underground, a realm where monsters were banished after war broke out with humans. The Underground is sealed from the surface by a magic barrier with a singular gap at Mount Ebott. A human child falls into the Underground and encounters Flowey, a sentient flower who teaches the player the game's mechanics and encourages them to raise their "LV", or "LOVE", by gaining "EXP" through killing monsters.