- Avenger is a monster truck currently racing in the USHRA Monster Jam series. It is currently driven by Jim Koehler. It was the first privateer truck to win a championship at the Monster Jam World Finals, winning the Freestyle championship in 2003. The truck is a teammate to Brutus. Avenger has been to all eight of the Monster Jam World Finals, and is extremely popular for its wild freestyle performances. Formerly a Chevy S-10 pickup, in 2002 it changed to its current body style, a 1957 Chevy Bel Air.