A guy who enjoys anal sex. It refers to the guy on the giving end, not the man or woman on the recieving end. This term is used to discribe gay and straight men. A well known synonym is "fudge-packer".
Guy 1: "Dude, i was with this chick the other night. Long story short, I licked her asshole to get her excited and then I stuck it in her ass to finish her off."
Guy 2: "Wow, I had no idea you were a Keebler Elf."
When a man shits on another man's penis. Then the man jerks off the penis he shit on. After that, the shitty penis is then inserted in the other man's ass.
"Wow, I met this guy last night and he showed me the Keebler Elf Trick."
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.