Okay I am sticking with 0 Hp as a possibility, making this card essentially pointless on a 1|1 creature, which is fine.
With no other input, I have decided the creatures will be random creatures with any ability they would normally come with. Of course their stats will be random and sum to the original creatures. The new creatures would be upped if the original creature was upped, and unupped if the original creature was unupped.
Any last minute thoughts? I am putting it in the crucible if not.