Viridian Emissary is a common Creature — Phyrexian Elf Scout card from Mirrodin Besieged (MBS), collector number 95. Current market price: $0.30 (foil $1.05), TCGplayer market prices via Scryfall.
When this creature dies, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.