I agree, it doesn't look like someone could go to the back of that thing so it couldn't be a mongoose. And by the way, what is the name of that whistling song. It's the bomb.
The thing he gets on is called a mongoose, Theres a whole article on bungies site about them. A person can drive the vehicle. There are no weapons, But a person can sit on the back and use a weapon he had in his hand or on his back to shoot people with. You can also transport the flag on this to get it across the map faster
