Yeah What is a lime green, translucent, floating monster that appeared in Replying Properly, a segment of Growing Up With Hello Kitty. His favorite kids always reply "Yeah, what?", and whenever he hears someone say those words, he gets bigger. This scared Kitty, until he shrank down to nothing. To make him shrink, say the word "Yes", which also scares him. It is unknown what he wants, or if he is a real threat, but he is intimidating. He has a round body with a tapering tail and no legs or feet, with thin arms up high, ending in hands, and a round head on top, with a tapering point on the tip. He has large yellow eyes, and a mouth, and a deep, slightly nasal, masculine voice.