Supply Caravan
Amonkhet — common
Creature — Camel
Supply Caravan rulings:
2017-04-18: If you don’t control a tapped creature as Supply Caravan enters the battlefield, its ability doesn’t trigger, even if you can tap a creature right away. If you control no tapped creatures as the ability resolves, nothing happens.
2017-04-18: If an effect causes Supply Caravan to enter the battlefield tapped, it will satisfy its own triggered ability.