Master Code (GBA)
948837FFA22A
99B2517F0C5F
FF17E5D8129F
This code will let you enter any other Gameshark codes for Barnyard.
Infinite Money (GBA)
166CF2664086
This code will give you an infinite supply of money to spend in the game.
Infinite Supply of Health and Stamina (GBA)
Infinite Health:
90BB7B0B56B3
Infinite Stamina:
C0937A0053B3
Obtain all Items in Game (GBA)
D48B5BE85BB4
B9BA204A018D
This code will make it so that you will have every single item in the game.