Yedora, Grave Gardener, Tribal Forcemage, and Ashnod's Altar

Prerequisites

• Yedora, Grave Gardener on the battlefield
• Tribal Forcemage on the battlefield
• Ashnod's Altar on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Tribal Forcemage, adding
2. Tribal Forcemage dies, triggering Yedora, returning Tribal Forcemage to the battlefield face down as a Forest land with no other types or abilities
3. Activate Tribal Forcemage by tapping it, adding
4. Activate Tribal Forcemage's megamorph ability by paying , turning it face up with a +1/+1 counter on it
5. Tribal Forcemage triggers, giving all creatures you control of a chosen creature type +2/+2 and trample until end of turn
6. Repeat

Results

• Infinite colorless mana
• Infinite death triggers
• Infinite ETB
• Infinite landfall triggers
• Infinite LTB
• Infinitely large creatures until end of turn
• Infinite sacrifice triggers