Ulamog, the Infinite Gyre (Topper) [Ultimate Masters Box Topper] Friday Night Magic 2011 Isleback Spawn gets +4/+8 as

Isleback Spawn gets +4/+8 as long as a library has twenty or fewer cards in it

If an instant or sorcery source would deal 3 or more damage to you

Set: Dominaria Prerelease Promos Type: Legendary Sorcery Rarity: Rare Cost: {4}{W} (You may cast a legendary sorcery only if you control a legendary creature or planeswalker

and you may spend mana as though it were mana of any type to cast that spell

Ulamog, the Infinite Gyre (Topper) [Ultimate Masters Box Topper] Friday Night Magic 2011 Isleback Spawn gets +4/+8 asSet: Ultimate Masters Box Topper Type: Legendary Creature Eldrazi Rarity: Mythic Cost: {11} When you cast this spell, destroy target permanent. Indestructible Annihilator 4 (Whenever this creature attacks, defending player sacrifices four permanents.) When Ulamog, the Infinite Gyre is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.