for one to be "elfed" the person is fucked up on all levels of the spectrum. in their own little black, brown, or greyed out world. it comes from mixing excessive alcohol, marijuanna, and any other kinds of uppers or downers at the same time. though this is usually a good time it usually will only be remembered through stories and pictures of ones elfed up self.
"dude i dont remember anything from last night, i was so elfed!"
when you pass out at a party or your house (pretty much anywhere you're with people) with your shoes on, and the people awake fuck you up! they might draw all over your face, spray paint your shoes, take hilarious photos of you in embarrassing poses, all while you're passed out. the possibilities of burning you are endless.
"oh, god, I drank too many sea breezes last night and woke up with a hitler mustchace sharpied on my face. i was Elfed up good."