If you're at the top of the highest bulding you can find, jump off and rapidly press Square. You should be able to fly for a few short seconds before you fall back to the ground.
While playing, pause and hold the R1 button and press Triangle, Square, Square, Circle, Circle, X, X, Triangle. You should hear a roar, continue play and you will have infinite life!
All monsters have allergies. When your monster eats the thing he or she's allergic to he or she will sneeze and it will blow down the building you are on.
George is allergic to dogs.
Lizzy is allergic to birds.
Ralph is allergic to cats.
*Play as a giant dog:
Press Up, Down, Left, Up, Up, Up and then X, X when the game is loading to the first level. You will then be a giant dog.