One who's age matches their IQ. They often have a "420" somewhere in their user name. A person who joins an Internet message bored to do nothing but asks stupid inane questions. This person is regarded as flame bait.
Origin: An infamous puppet of the same name.
"What's with the flood of inane questions today?"
"It's this new user, he has to be 15 years old... he's such a beerweed."