Thanks to JayFoxRox for finding these codes out 20 years after the initial release! Cy Yunga and Jinn Reeso are secret Pod Racers that replace 'Bullseye' Navoir and Mars Guo respectively. They share the same exact stats as the pods they replace so picking them is only cosmetic from what I can tell. However, the shape of their pods is quite different from those that they replace so they might have new hitboxes but I can't say for certain.

Anyway to unlock them:

- Cy Yunga press Left-Ctrl, C and Y together on the character select screen
- Jinn Reeso press Right-Ctrl, N and K keys on the character select screen

The code isn't permanent and will have to be reactivated everytime you start the game. It also works in Multiplayer but it only works for the player that did the code, so if two people pick Cy Yunga and Bullseye Navior the Cy Yunga player will see 2 Cy Yungas and the Bullseye player will see 2 Bullseyes.