Yedora, Grave Gardener, Phyrexian Altar, and Goblin Taskmaster

Prerequisites

• Yedora, Grave Gardener on the battlefield
• Phyrexian Altar on the battlefield
• Goblin Taskmaster on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing Goblin Taskmaster, adding
2. When Goblin Taskmaster dies, Yedora triggers, returning Goblin Taskmaster from your graveyard to the battlefield face down as a Forest land
3. Activate Goblin Taskmaster by tapping it, adding
4. Activate Goblin Taskmaster'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