Cumquad
Cumquad is an obscure insult meaning "jerk" stemming from the internet. The most likely origin of this insult is the misspelling of "Kumquat!" which can also be used as an insult.

Someone who is rude, not fun to be around; a straight up asshole.

Not to be confused with the bright orange fruit, "Kumquat" (alternatively spelled cumquat).
Person 1: Chad is being such a cumquad, I'm leaving!
Person 2: He's such a jerk.