One step closer to Jurassic Park!
https://www.smithsonianmag.com/science-nature/the-history-of...
Mammoths only went extinct 10k years ago. They might be viable, though I imagine they wouldn't be happy with what industrialization has done to the air.
This would be pretty different from the ferret project, as the mammoth DNA available isn't in good shape. It would require genetic engineering as well as cloning, and mostly consist of introducing mammoth DNA into Asian elephants a few genes at a time.
Thylacine is pretty special as far as I know, with it being marsupial (though perhaps it is easier that way because a significant part of the development is outside the mother?)