Jeffrey

Jeffrey is usually used as a slang for Self-Improvement for someone that doesn't use his time to improve himself, and instead indulges in instant-gratification (Video games, masturbation, junk food, drugs etc...) and usually he also has poor mental health.
The antonym of Jeffrey in the Self-Improvement community is "Adonis"

- Emily: Omg guys!!! Gabriel is such a Jeffrey
-Gabriel: Hey!! Im not a Jeffrey!