Domesticated Hydra is a uncommon Creature — Hydra card from Conspiracy: Take the Crown (CN2), collector number 63. Current market price: $0.25 (foil $0.49), TCGplayer market prices via Scryfall.
{X}{G}{G}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.) As long as this creature is monstrous, it has trample.