Ghired, Mirror of the Wilds, and Great Oak Guardian

Prerequisites

• Ghired, Mirror of the Wilds on the battlefield
• Great Oak Guardian on the battlefield
• You have a way to create a token copy of Great Oak Guardian

Steps

1. Create a token copy of Great Oak Guardian
2. Activate Ghired by tapping it, creating a token copy of the Great Oak Guardian copy
3. When the Great Oak Guardian token enters the battlefield, it triggers, untapping all creatures you control and causing them to get +2/+2 until end of turn
4. Repeat from step 2

Results

• Infinite ETB
• Infinite creature tokens
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce
• Infinitely large creatures you control until end of turn