Wildheart Invoker is a common Creature — Elf Shaman card from Duel Decks: Elves vs. Inventors (DDU), collector number 26. Current market price: $0.31, TCGplayer market prices via Scryfall.
{8}: Target creature gets +5/+5 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)