Scouring Swarm + Beifong's Bounty Hunters + Phantom Train

Scouring Swarm

Beifong's Bounty Hunters

Phantom Train

How it works

1. Activate Phantom Train by sacrificing another nonland creature you control.
2. When the creature dies, Beifong's Bounty Hunters triggers, earthbending a land you control.
3. Resolve the Phantom Train ability.
4. Activate Phantom Train by sacrificing the earthbent land.
5. When the land dies, it and Scouring Swarm trigger.
6. Resolve the land's trigger, returning it from your graveyard to the battlefield tapped.
7. Resolve the Scouring Swarm trigger, untapping it and creating a creature token.
8. Resolve the Phantom Train ability.
9. Repeat.