cartoon

I don't understand it:
http://media.collegepublisher.com/media/paper864/stills/6e359mfk.gif

I don't get that "cosmo for cussy". The first thing that came to mind was "Cosmetics for pussy?" and subsequent references to menstruation, but I must be missing something. According to my dictionary, "Cosmo" is short for "Cosmopolitan", a kind of magazine, but I still can't be sure what the intended joke is. (Non-native speaker here)

Apparently Cussy is the character on the right, and Pox is the one on the left, their names being a rather juvenile word play.

A cosmo or cosmopolitan is a cocktail made of vodka, triple sec, and cranberry juice. Cussy is probably the comic strip character's name or nickname. Chocolate cravings supposedly intensify when women are in their menstrual cycle.

http://answers.yahoo.com/question/index?qid=20080202175851AAb20Uu

Cussy has period and Pox is in menopause, they both need comfort food, hence the chocolate. Why is this supposed to be funny I don't know.