Notes:

This is one of those cases where I'm surprised anyone is surprised. The Ponyheads are biologically Monsters (they are not legally treated like Monsters due to a treaty the Ponyheads signed with Prince Jushtin), and Monster powers are not tied to Mewman Magic. Recall that Toffee was able to use his regeneration powers even after he killed the Magic Realm during the Battle for Mewni.