Ambush Commander is a rare Creature — Elf card from Scourge (SCG), collector number 111. Current market price: $2.29 (foil $7.92), TCGplayer market prices via Scryfall.
Forests you control are 1/1 green Elf creatures that are still lands. {1}{G}, Sacrifice an Elf: Target creature gets +3/+3 until end of turn.