Joop Kasteel

Joop Kasteel, also known as "de zwarte parel" ("the black pearl", born 27 August 1964), is a Dutch former mixed martial artist. He made his mixed martial arts debut on 15 June 1996. He is a veteran of the RINGS promotion and as he has fought the majority of his fights for them.

Kasteel's trainers were Chris Dolman, Hans Nijman and Michel van Halderen he also stated he trained with "Dirty" Bob Schrijber. As a former bodybuilder he went into the MMA world & became one of the most popular Dutch fighters noted for his power and physique, normally weighing in at around 265 lbs.