Sarcaholic
A person who being so sarcastic seems actually crazy.
Peter: the lawyer it is so unprofessional, I do not know if he is, actually, acting nuts or just being sarcaholic.
Sarcaholic
Noun (n): A person with an addiction to being sarcastic or giving sarcastic responses.
Hi..my name is Keara and I'm a sarcaholic. I'm so allergic to stupidity that I can't help but respond with sarcasm.