At the beginning of your upkeep, reveal the top card of your library. If it's a creature card that shares a creature type with a creature you control, you may cast that card without paying its mana cost. Otherwise, put that card on the bottom of your library.
![Descendants' Path [Avacyn Restored] | The Clever Kobold](http://thecleverkobold.com/cdn/shop/products/ada93208-5cda-4e2d-b9a7-15345e30b831.jpg?v=1574226407)
