Yedora, Grave Gardener, Phyrexian Altar, and Headhunter

Prerequisites

• Yedora, Grave Gardener on the battlefield
• Phyrexian Altar on the battlefield
• Headhunter on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing Headhunter, adding
2. When Headhunter dies, Yedora triggers, returning Headhunter from your graveyard to the battlefield face down as a Forest land
3. Activate Headhunter by tapping it, adding
4. Activate Headhunter's morph ability by paying , turning it face up
5. Repeat

Results

• Infinite death triggers
• Infinite green mana
• Infinite landfall triggers
• Infinite LTB
• Infinite sacrifice triggers