The Aether Flues (March of the Machine Commander 139) - Common

When you planeswalk to The Aether Flues and at the beginning of your upkeep, you may sacrifice a creature. If you do, reveal cards from the top of your library until you reveal a creature card, put that card onto the battlefield, then shuffle all other cards revealed this way into your library.
Whenever chaos ensues, you may put a creature card from your hand onto the battlefield.