Yenna, Redtooth Regent, Agatha's Soul Cauldron, Ashnod's Altar, and Great Oak Guardian

Prerequisites

• Yenna, Redtooth Regent on the battlefield
• Agatha's Soul Cauldron on the battlefield
• Ashnod's Altar on the battlefield
• Great Oak Guardian on the battlefield
• plus enough mana to activate the Licid's ability
• available

Steps

1. Activate Great Oak Guardian using the Licid's ability by paying its activation cost, attaching Great Oak Guardian to Yenna and causing Great Oak Guardian to become an Aura
2. Activate Yenna by paying and tapping it, creating a token copy of Great Oak Guardian
3. When the Great Oak Guardian token enters, it triggers, untapping all creatures you control and giving them +2/+2 until end of turn
4. Activate Ashnod's Altar by sacrificing the Great Oak Guardian token, adding
5. Repeat from step 2

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce
• Infinite power and toughness for creatures you control until end of turn