n00b13
A person who doesn't know what they're doing but still thinks they're the best. They're like a chicken who thinks they're a superhero but just clucks at the villain.
"You're a n00b13. You don't even know what a sword is."
In chat: "This guy is a n00b13. He tried to fight me with a hat."
DM: "You're a n00b13. You can't even use your own hands."