Ancestral Den

Echo {r}{g} (At the beginning of your upkeep, if this
came under your control since the beginning of your
last upkeep, sacrifice it unless you pay its echo cost.)
Whenever Ancestral Den enters the battlefield,
or you pay a permanents echo cost, reveal the top
card of your library. If a creature or land card is
revealed this way, you may put it into your hand
or graveyard. Otherwise, put it on the bottom of
your library.