Chameleon Queen used to be a very small until she ate too many flies making her huge commanded by High Roller to eat the flies. She eventually gained armor from a bell making her the most valuable member of High Roller's army. As Shown in The Bronze Giant, she has joined Big Green.
Chameleon Queen has shown to have a long tongue which can be used as a weapon. Also if she gets someone inside her, she is capable of controlling her internal organs.