Depthdweller Matriarch

When Depthdweller Matriarch enters the battlefield, search your library for a Merfolk
creature card, reveal that card, put it into your
hand, then shuffle your library.
Whenever a Merfolk you control enters the battlefield, you may search your library for a
Merfolk creature card, reveal that card, put it
into your hand, then shuffle your library.
"Rise, my children."