so this is another art of millie just being very silly and herself, and yes she have a gas inside of her body, it's a airbag inside of her. the gas can be used for turning opponent is intro rubber.

she is not a enderdragon, or a humanoid, she is a gassy-dragon, like squeeze-shark (this is shane's nickname)

that give me a inspiration of one of dlrowdog art of this: https://www.furaffinity.net/view/55748316/
(it's the 4th image)

i am confirming millie have a airbag power (I mean she still elastic but with a second power), because why not? :3