Caffreener 

Someone who is addicted to caffeine, but has chosen to abstain in order to remain free from the downsides of caffeine addiction.

Do you want a coffee mate? No - I used to drink a lot of coffee, but now I’m a caffreener.

Caffreener by bulbousity December 16, 2023

Caffeiner 

A person who drinks a lot of coffee, probably is addicted to caffeine and hates decaf.

"What? That's your 5th cup.

You are a caffeiner, aren't you?"

Caffeiner by seiju December 25, 2017