The Lost Caverns of Ixalan Commander

Descendants' Path

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 it without paying its mana cost. If you don't cast it, put it on the bottom of your library.

Secret Lair Drop

Avacyn Restored

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.