The following are known Action Replay Codes for The Simpsons: Night of the Living Treehouse of Horror 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

Stop Timer
932b31d0

Infinite Health
9120a5c2

Infinite Lives
91099cc2

No Items To Be Collected
9100c6c1

Max Score
913903d0
913904d0
913905d0
913906d0
913907d0
913908d0