Jabba-mouth
A person who runs their mouth like they know what they're talking about and they're in the right when in reality they are dead wrong and misinformed.

Characteristics of a jabba-mouth

1. Extremely stubborn
2. Won't admit being wrong even when they are
3. They get angry when people disagree with them
4. No tolerance or respect for other opinions/beliefs that clash w/ their own
John: The sky is blue

Jabba-mouth: No it's not it's brown

John: It's a known fact and anyone can clearly see.........

Jabba-mouth: F**K YOU DOUCHEBAG IT'S BROWN!!!!