Enter an unlocked forest area. Press 2 to pause the game. Select "Enter Codes" at the menu, then enter one of the following codes to activate the corresponding cheat function:
Enter "FERRET" as a code to unlock the Ferret.Panda
Enter "Panda" as a code to unlock the Panda.Red Panda
Enter "Red Panda" as a code to unlock the Red Panda.