An emoti-mime, short for "Emoticon Pantomime", is an evil person who only replies to your IM's on something like AOL Instant Messenger, ICQ, IRC, or even the chatterbox, with Emoticons ONLY.

SomeAIMGuy: Hey, how's it going?
Emoti-mime: ;-)
SomeAIMGuy: Err... is that good?
Emoti-mime: 8-)
SomeAIMGuy: What the hell? Are you smoking something?
Emoti-mime: O:-)
SomeAIMGuy: I'll break that freakin' halo over your ears if you don't say something
Emoti-mime: =-O
SomeAIMGuy: Don't act so f#@^ing shocked. You're obnoxious
Emoti-mime: :-X

As you can see, an emoti-mime can cause just as much pain and frustration as a real mime. Also, this brings up a new version of the age old question, "If someone ping floods an emoti-mime to death somewhere on the internet, does anyone care?"