To me, they look like green bells, turned upside down, and tilted to the left?!?!?!
Do you know the link to the avatar progression chart? Ziroc posted it in a GD thread once before but I hate to go digging around if you, my knowledgible friend, can save me the trouble
Oh, and your point about the "bottom" pictures and the hairy tail is kind of scary...lol.