The following are known Action Replay Codes for Croc 2 on Nintendo Game Boy / Color (GB / GBC). These codes were also known as GameShark Codes and in most cases will work on both devices.

Device Compatibility: Action Replay & GameShark

Infinite Lives
9163f0c9

Infinite Health
9103eec9

Max Attack Points
9163f6c9

Lots of Crystal Points
91ffb4ca

Have All Five Crystals for All Levels
91ffe3c9