Unswerving Sloth is a uncommon Creature — Sloth Mount card from Aetherdrift (DFT), collector number 34. Current market price: $0.19 (foil $0.21), TCGplayer market prices via Scryfall.
Whenever this creature attacks while saddled, it gains indestructible until end of turn. Untap all creatures you control. Saddle 4 (Tap any number of other creatures you control with total power 4 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)