A girl who REALLY wants it. Cookiemonsters are primitive creatures that are found mainly in regions categorized by Suburban Jewopolisness. In many cases, Cookiemonsters will act violently when they are refused it.*
There are various ways of determining whether or not a girl is in fact a Cookiemonster. One of which is by simply observing their acts. Should a girl stand in the corner, straddling a filing cabinet, she is probably a HUGE Cookiemoster.
*The fact that Cookiemonsters want it does not at all require attractive rowers to give it to them.
1: That Cookiemonster wants to crumble.
2: Don't buy those clothes, that's what a Cookiemonster would wear.
3: Don't give it to that girl, she's a big Cookiemonster.