(Adj.) Someone who exaggerates the truth. A person whom most often then not, always has a story to tell in relation to the conversation, most often the story is made up or a gross exaggeration of the truth.
"Bob, did you see that J.F.K. Documentary?" "My brother's roomates uncles, fathers, sister, friends, aunt is best friends with J.F.K." "Damn, Bob you are such a cacker!"