In order to obtain a Pengatrice egg you must use the Spirit cobra's special ability on a Penguin egg (requires level 63 Summoning). The pengatrice egg is one of the easiest eggs to create. You may talk to the Penguin Keeper at the Ardougne Zoo to get a free penguin egg from him, although he will not give the player a penguin egg if the player already has a penguin egg in inventory, in the bank, or in an incubator, or has a baby or adult penguin following the player, in inventory, or in the bank. However, if the player has an adult penguin, placing it in the Pet house of a Player-owned house will allow the player to get another penguin egg from the keeper.