Instructions
Use the stylus on the bottom screen to create any sort of animal by writing its name. For example, type in "Ostrich," press "Enter" and the game will confirm that you want "Ostrich (bird)."
Allow the animal to be killed by any enemy onscreen. The corpse will remain for a while, rather than disappearing. Alternatively, if you kill any animal-type enemy, the same will happen.
Type in "necronomicon," and the game will ask you to confirm "Necronomicon (book)." Select the Necronomicon, which is a book of spells, and use it on the dead animal. It will be resurrected as a skeleton animal warrior.