Ulamog's Dreadsire, and Intruder Alarm

Prerequisites

• Ulamog's Dreadsire on the battlefield
• Intruder Alarm on the battlefield
• Ulamog's Dreadshire does not have summoning sickness

Steps

1. Activate Ulamog's Dreadsire by tapping it, creating a 10/10 Eldrazi creature token
2. When the Eldrazi enters the battlefield, Intruder Alarm triggers, untapping all creatures
3. Repeat

Results

• Infinite creature tokens
• Infinite ETB
• Infinite mana creatures you control can produce
• Infinite untap of all creatures