Aluren + Cloudstone Curio

Prerequisites

You control a nontoken nonartifact creature with mana value 3 or less. You have a nonartifact creature card with mana value 3 or less in your hand.

Steps

1. Cast any nonartifact creature with mana value three or less from your hand by paying {0} due to Aluren.
2. When the creature enters the battlefield, Cloudstone Curio triggers, returning another nontoken nonartifact creature with mana value three or less.
3. Repeat.