Ghired, Mirror of the Wilds, and Steelfin Whale

Prerequisites

• Ghired, Mirror of the Wilds on the battlefield
• Steelfin Whale on the battlefield

Steps

1. Create an artifact token
2. When the artifact enters the battlefield, Steelfin Whale triggers, untapping itself
3. Activate Steelfin Whale by tapping it, creating a copy of the artifact token
4. Repeat from step 2

Results

• Infinite copies of artifact tokens you control that entered the battlefield this turn