Neyith of the Dire Hunt is a rare Legendary Creature — Human Warrior card from Jumpstart (JMP), collector number 30. Current market price: $13.41, TCGplayer market prices via Scryfall.
Whenever one or more creatures you control fight or become blocked, draw a card. At the beginning of combat on your turn, you may pay {2}{R/G}. If you do, double target creature's power until end of turn. That creature must be blocked this combat if able. ({R/G} can be paid with either {R} or {G}.)