Nyxborn Hydra (164) [Modern Horizons 3]

Bestow {X}{G}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.) Reach, trample This permanent enters with X +1/+1 counters on it. Enchanted creature gets +1/+1 for each +1/+1 counter on this Aura and has reach and trample.