How to get rid of emoji (emoticons) in Terminal.app (OS X 10.9)
Emoji are simply unicode characters that are rendered as such by the operating system. In the following screenshot, you can see that unicode is "allowed" in filenames:



In fact, these are even rendered by Finder:



To fix this, simply rename the file through Finder or Terminal. 

This happens because whatever glyph substitution algorithm that they use is picking up the unicode text in the filename and replacing it with Emoji (which is a ttf font on OS X).