Mark "The Shark"

Mark "The Shark" Irwin is an American bare-knuckle boxer and the inaugural BYB Extreme Lightweight World Champion. Training out of Huntington Beach, California, under former UFC fighter Ian McCall, Irwin has built a reputation as one of the most exciting and resilient fighters in combat sports. He is easily recognized in the ring by his signature leopard-print dyed hair, extensive tattoos, and a relentless, high-pressure fighting style that frequently pushes his bouts into territory revered by hardcore fight fans. Irwin's career is defined by his willingness to engage in brutal, toe-to-toe battles. His grueling fights against Julio Tanori in 2022 and 2023 earned widespread acclaim, including Fight of the Year honors from the Bare Knuckle Boxing Hall of Fame. Outside of his professional fighting career, Irwin is a dedicated advocate for athlete wellness. He actively collaborates with nonprofit organizations focused on traumatic brain injury (TBI) recovery, promoting therapeutic treatments and mental health support for fellow combat athletes.