I need some help fleshing out the mechanic for this card:

I have a basic idea of what it should do. Dying non

creatures get transformed into

creatures instead of leaving play.
I know that I want pharaohs to convert to mummies and dragons to convert to bone or ivory dragons, but I'm not sure how to handle mapping other creatures.
This would override creature abilities / traits such as phoenix, aflatoxin, and cat (poor kitty gets mummified… should be funny!)
Any suggestions for an intuitive scheme would be appreciated.
The main idea is that players should get back a

creature of roughly equal "worth" as the creature that died.
I haven't decided whether it fits best as a

card or a hybrid

and

card… Creating undead minions seems pretty dark after all.