They're amongst the toughest sports stars in the world - taking part in brutal fights in packed stadiums and watched by millions on television.
And the leading lights of the Mixed Martial Arts (MMA) world can earn millions of dollars with their talent.
Add in money-spinning fights against big name boxers, advertising and sponsorship deals, and shrewd investments, and these fearsome warriors can become fabulously wealthy.
Here are the top 10 MMA stars in the world in 2024, according to CelebrityNetWorth.
1. Conor McGregor
Ireland's Conor McGregor is by far the biggest - and richest - name in MMA. The star of recent film Roadhouse is worth a remarkable $200 million. His 2017 fight agains boxer Floyd Mayweather alone is thought to have earned him in the region of $100 million.
2. Khabib Nurmagomedov
Russian fighter Khabib Abdulmanapovich was the longest-reigning UFC Lightweight Champion ever, holding the title from 2018 to 2021 with 29 wins and no losses. He's currently retired undefeated and is worth approximately $40 million.
3. Brock Lesnar
Multitalented Brock Lesnar has enjoyed a varied career spanning MMA, American Football and wrestling. Currently signed up to have won the heavyweight championships of WWE, Ultimate Fighting Championship (UFC), New Japan Pro-Wrestling (NJPW),the Inoki Genome Federation (IGF), and the National Collegiate Athletic Association (NCAA). Aside from the belts, it's earned him a fortune of around $20 million.
4. Georges St-Pierre
Known simply as GPS, retired Canadian fighter Georges St-Pierre is one of the all-time great of MMA - having won titles in both the Ultimate Fighting Championship welterweight and middleweight divisions. His record of 26 wins from 28 fights has earned him in the region of $20 million.