Immortal Leviathan

The Immortal Leviathan is a secret pet in Pet Hatching Madness. It can be hatched from the Immortal Egg. The chances of hatching it is 0.0001% (1 in 1,000,000). The chances of hatching a mythic version of it is 0.000025% (1 in 4,000,000?)

Trivia:

 * There is only one confirmed hatch of this pet.
 * This is the rarest pet in the Immortal Egg.