A Mat Rempit is a Malaysian term for "an individual who participates in activities such as illegal street racing, bike stunt performance, petty crime and public disturbance using a motorcycle", usually involving 2- and 4-stroke underbone motorcycles, colloquially known as Kapcai or scooters.
Mat Rempits are often seen on Malaysian streets, where they would gather in groups and race against each other for cheap thrills such as races and stunts (such as the wheelie, superman (lying flat on the seat), wikang and scorpion (standing on the seat with one leg during a wheelie). However, there are cases where they openly rebel against authorities where they would run through roadblocks, ride against the traffic or hit police officers with their bikes. Mat Rempits often race or perform stunts without proper safety gear and properly-equipped bikes, which often lead to accidents, causing major injuries or death.

View More On Wikipedia.org