Never believe the information about breeding in the animal description when they bring them out of retirement. They don't bother updating the animal descriptions.
I have had no luck for the Pastel Penguin on any of my 3 accounts, so I decided to bring fire into the mix and see if I can breed either it or the Racchrome. Trying REALLY hard not to let myself get frustrated over days and days of fruitless breeds.
I DID manage to breed a Sapphire Cthulhu several days ago, but it was on an account where I already had 2 of them and no immediate home for a 3rd, so I sold it.
How I hated to do that!