Skyrider Elf is a uncommon Creature — Elf Warrior Ally card from Battle for Zendikar (BFZ), collector number 220. Current market price: $0.22 (foil $0.35), TCGplayer market prices via Scryfall.
Flying Converge — This creature enters with a +1/+1 counter on it for each color of mana spent to cast it.