Board Thread:General Discussion/@comment-26006155-20181123023529/@comment-26006155-20181123153016

Mini-addition about why Napstablook must have a monster soul:

Napstablook the snail farmer also remembers a time when his best customer left, long ago, and now his only customer is a big hairy guy who visits once a month. Toriel is the one famous for her snail cuisine, and if boss monster Asgore is the only other one in the Underground who eats snails, that means Napstablook is an old ghost who remembers life before Chara, the first human, arrived, and witnessed Toriel and Asgore’s breakup.

Which means Napstablook isn’t the ghost of any of the fallen humans.