There is only one 'Impossible' difficulty-level Hidden Egg, and it is known as the Angel Egg. It can be found on the 'Stairway to Heaven,' and it has a random chance of spawning each time the Egg Hunt ...

Typically, the hatch rates of Secret Pets are as low as one in a billion or even lower, for certain Pets. While this can be mitigated somewhat, you will still need to rely on pure chance to acquire ...