Circle of Dreams Druid, and Umbral Mantle

Prerequisites

• Circle of Dreams Druid on the battlefield
• Umbral Mantle on the battlefield
• Umbral Mantle attached to Circle of Dreams Druid
• Circle of Dreams Druid does not have summoning sickness
• You control at least four creatures

Steps

1. Activate Circle of Dreams Druid by tapping it, adding at least
2. Activate Circle of Dreams Druid by paying and untapping it, giving itself +2/+2 until end of turn
3. Repeat

Results

• Infinitely large Circle of Dreams Druid until end of turn
• Infinite green mana