Mesmeric Orb, and Tidewater Minion

Prerequisites

• Mesmeric Orb on the battlefield
• Tidewater Minion on the battlefield
• Tidewater Minion does not have summoning sickness

Steps

1. Activate Tidewater Minion's last ability by tapping it, untapping itself
2. When Tidewater Minion becomes untapped, Mesmeric Orb triggers, causing you to mill a card
3. Repeat

Results

• Infinite self-mill