I have read other guides and such, and have a general idea of what to expect from crossing level 48 pets, but tis one makes me wonder. I have a wraith, I crossed it with a Helephant and got a death oni. If I read properly, this is normal. I then hatched my wraith with a hydra, and got another death oni. From what I read, this is not normal.
From my experience, you will more often get the same pet (of a different pedigree) then you will get a new pet. Especially true when trying to get a completely new, ie rare, pet. So just count yourself lucky that you got a rare pet on your first try. :)
I SO HAVE TO GET A SORCERER AND LEVEL UP MY WRAITH TO GET A DEATH ONI!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
