Spawnsire of Ulamog (ROE-011)

Annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent of their choice.)
: Create two 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this token: Add ."
{20}: Cast any number of Eldrazi spells from among cards you own outside the game without paying their mana costs.