Umm, no. You can also mix and get a Hybrid with LVL 48 Pets. Such as.. Helephant + Wraith = Fire Wraith (Something like that) Sincerely, Elizabeth MistLeaf (Level 49 Master of Ice)
archfiend. And if you mix a piggle with a fog unicorn, chances are you get a piggle back with some of the unicorn's traits mixed in
The only way to be sure to get a compleatly different pet is to mix two special offer exclusive pets, two frog unicorns would work. The special offer exclusive pets cannot be hatched so the game is forced to give you something different. No one has said what those different pets are though. The official announcement about it was vague about that particular point.