Bristling Hydra is a rare Creature — Hydra card from Kaladesh (KLD), collector number 147. Current market price: $0.16 (foil $0.33), TCGplayer market prices via Scryfall.
When this creature enters, you get {E}{E}{E} (three energy counters). Pay {E}{E}{E}: Put a +1/+1 counter on this creature. It gains hexproof until end of turn.