Beifong's Bounty Hunters + Phyrexian Altar + Felidar Retreat

Beifong's Bounty Hunters

Phyrexian Altar

Felidar Retreat

How it works

1. Activate Phyrexian Altar by sacrificing another nonland creature you control.
2. When the creature dies, Beifong's Bounty Hunters triggers, earthbending a land.
3. Activate Phyrexian Altar by sacrificing the land.
4. When the land dies, Beifong's Bounty Hunters triggers, returning the land from your graveyard to the battlefield tapped.
5. When the land enters, Felidar Retreat triggers, creating a creature token.
6. Repeat.