An evil, stupid, and lazy elementary teacher
(6th grade usually) who steals money from her students and has all of the qualities of your most hated teacher. You can easily tell if you have a Mosser because...
1. she is overweight, has orange-ish hair, and painted on eyebrows
2. she spends more time on her laptop than teaching
3. she finds enjoyment in punishing kids for every little thing, whether they are guilty or not
Kelso: "Ugh. do you remember our 6th grade teacher? You know, the one who stole $20 from me that one time?"
Alice: "Yeah. How can you forget Mosser? She was like pure evil... i swear!"