Llanowar Scout + Dimir Aqueduct + Elven Raft-Steerer

Llanowar Scout

Dimir Aqueduct

Elven Raft-Steerer

How it works

1. Activate Llanowar Scout by tapping it, putting Dimir Aqueduct from your hand onto the battlefield.
2. When Dimir Aqueduct enters the battlefield, it and Elven Raft-Steerer trigger.
3. Resolve the Dimir Aqueduct trigger, returning itself from the battlefield to your hand.
4. Resolve the Elven Raft-Steerer trigger, untapping Llanowar Scout.
5. Repeat.