Avalanche Riders is a uncommon Creature — Human Nomad card from Urza's Legacy (ULG), collector number 74. Current market price: $0.47 (foil $28.24), TCGplayer market prices via Scryfall.
Haste Echo {3}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.) When this creature enters, destroy target land.