If any wrestling game was able to reach the delicate balance of weirdness and awesomeness that NBA Jam achieved with their diverse cast of unlockable players - which included Mortal Kombat characters, the Beastie Boys, the Fresh Prince of Bel-Air, and several high-ranking government officials - it was WCW/nWo Thunder.
Developers at Inland Productions apparently threw everything they had at the wall to see what would stick, then scraped up the splattered remains of the things that fell to the floor, superglued them back onto the wall, and put the entirety of said wall into the game.
It had a ton of innovations that gamers had never seen before, including new match types, intensely specific customization, and the wackiest roster in the history of wrestling games.
Along with the entire WCW/nWo roster - which in 1998 was already growing to unmanageable levels in real life - they also included the Nitro Girls, various WCW crew members, two dozen THQ/Islander staff members, multiple robots, a stained glass window come to life as a human, an astronaut, conjoined twins, a horse named Hoof Hearted (get it!?), a cow, a pig man, a starfish, multiple insects, a skeleton, and a knight. Wowsers.