An adjective typically used to describe Vampires, Werewolves, Zombies, girls who bite you, and any vicious animal. It derives from the two words "dangerous" and "fang."
This is a less offensive way of saying "smell my fingers". It's still offensive and if you are able to get someone to do it then that person is a fool. They may have been touching their butt crack doing a stink check.
Guy 1: Hey man smell my fangers. Guy 2: Man that's nasty.