Umbral Mantle, Zhur-Taa Druid, and Agatha of the Vile Cauldron

Prerequisites

• Umbral Mantle on the battlefield
• Zhur-Taa Druid on the battlefield
• Agatha of the Vile Cauldron on the battlefield

Steps

1. Activate Zhur-Taa Druid by tapping it, adding
2. Zhur-Taa Druid triggers, dealing 1 damage to each opponent
3. Activate Zhur-Taa Druid by paying and untapping it, giving it +2/+2 until end of turn
4. Repeat

Results

• Infinite damage
• Infinitely large creature until end of turn