Wurmcoil Engine (Toppers) [Double Masters Extended Art] Unicorn {3}{R/W}{R/W}: Creatures your opponents control

{3}{R/W}{R/W}: Creatures your opponents control block this turn if able

Ulvenwald Hydra's power and toughness are each equal to the number of lands you control

This explains why the goblins remain unaffected

(It can't be blocked except by creatures with flying or reach

Wurmcoil Engine (Toppers) [Double Masters Extended Art] Unicorn {3}{R/W}{R/W}: Creatures your opponents controlSet: Double Masters Extended Art Type: Artifact Creature Wurm Rarity: Mythic Cost: {6} Deathtouch, lifelink When Wurmcoil Engine dies, create a 3 3 colorless Wurm artifact creature token with deathtouch and a 3 3 colorless Wurm artifact creature token with lifelink.