Curse of Thalassophobia

Enchant Player
Whenever an island enters the battlefield,
enchanted player gets a Phobia Counter.
Sacrifice Curse of Thalassophobia: Create Cthulhu,
a 10/10 legendary black Avatar creature token
with flying and annihilator 3. Activate this ability
only if enchanted player has 10 or more Phobia Counters.