I see this card as a good engine for these decks, and even if it dies, you still get Temple of the Dead and the ability to transform it again later
Necropanther can give you a similar, early game mutate trigger, while Boneyard Lurker returns any permanent type, albeit to your hand
Arcanine ex costs 500 Pack Points to craft
Alacrian Jaguar Archmage's Newt Autarch Mammoth Bounding Felidar Bridled Bighorn Brightfield Glider Brightfield Mustang Bulwark Ox Calamity, Galloping Inferno Caustic Bronco Congregation Gryff Drover Grizzly Fortune, Loyal Steed Giant Beaver Gila Courser Gilded Ghoda Gloryheath Lynx Guardian Sunmare Lagorin, Soul of Alacria Ornery Tumblewagg Quilled Charger Rambling Possum Routeway Moose Seraphic Steed Stubborn Burrowfiend Switchgrass Grazer The Gitrog, Ravenous Ride Trained Arynx Unswerving Sloth Venomsac Lagac There are also several cards that care about mounts, but without being mounts themselves: In Steer Clear you have a bit of cheap removal spell that gets better with a mount
You may or may not see these in your EOE Prerelease and Sealed events given the fact that theyre mythic, but it should be fun to figure out which decks should run our favorite planets
