Drover Grizzly is a common Creature — Bear Mount card from Outlaws of Thunder Junction (OTJ), collector number 161. Current market price: $0.16 (foil $0.28), TCGplayer market prices via Scryfall.
Whenever this creature attacks while saddled, creatures you control gain trample until end of turn. Saddle 1 (Tap any number of other creatures you control with total power 1 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)