Spawning Grounds, Intruder Alarm, and Blossom Dryad

Prerequisites

• Spawning Grounds on the battlefield
• Intruder Alarm on the battlefield
• Blossom Dryad on the battlefield
• Blossom Dryad does not have summoning sickness

Steps

1. Activate the land with Spawning Grounds attached by tapping it, creating a 5/5 Beast creature token
2. The Beast enters the battlefield, triggering Intruder Alarm, untapping all creatures
3. Activate Blossom Dryad by tapping it, untapping the land with Spawning Grounds attached
4. Repeat

Results

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