Horizon Explorer is a rare Creature — Insect Scout card from Edge of Eternities Commander (EOC), collector number 35. Current market price: $2.89, TCGplayer market prices via Scryfall.
Lands you control enter untapped. Whenever you attack a player, create a Lander token. (It's an artifact with "{2}, {T}, Sacrifice this token: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.")