Pessist

1. Someone or something that is REALLY being quite a bother, or has the characteristics and qualities that are REALLY quite bothering and a disturbance.
2. A bitch
Derived from the word pessimism, and the suffix -ist.

Synonyms:

Pest, nuisance

1. Anne: "You've been such a pessist today, Marie. Stuffing up the couches with weed in my home, then smoking all the rest of your cigarettes in the backyard of your home, and then hiding my money I was saving for the rest of the week in your pockets. Now you're giving me the poor baby dog eyes. Such a sad little girl thing to do. You're annoying. Quit smoking cigarettes and grow up."
Marie: "I don't like your attitude either. We're not being friends for the next 2 weeks."

2. Byciclist: "My ankle is such a pessist today! It has been bothering me the whole day. I shouldn't have gotten my ankle hurt!"