Elementals

When this creature enters, you may search your library for an Elemental card, reveal it, then shuffle and put that card on top.

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.

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.