Scroll down at the following link to see an explanation. I think it refers to the silly little dance in the cartoon specials where they are kind of hopping and shifting their heads from side to side.
Never learned this when I learned about the cha cha (but this is for a line dance, right?)... I suppose it could be interesting if you are really trying to do something with some flair or a little different... a little two footed hop with some head movement might be just enough to make the move look more interesting or improved when in a group. http://www.country-time.com/archives..._slide_(c).htm