Teenage Mutant Ninja Turtles 3: Mutant Nightmare Codes -

Cowabunga message:
Press (x2), (x2), , , , , , at the title screen. The turtles yell "Cowabunga!". 

Password notes:
Use the following key when entering the passwords.

L: Leonardo 
M: Michaelangelo 
D: Donatello 
R: Raphael 
S: Shredder 

Turn crystals into bird eggs:
Enter SRDSLLMS as a code. 

Turn crystals into pumpkins:
Enter DRSSMRLD as a code.

Turn crystals into snowmen:
Enter LLDMSRMD as a code.

Turn Life Icons into pizza:
Enter DDRMLRDS as a code.