Yienva, the Adventurer

Flying, first strike, vigilance
Whenever Yienva attacks, reveal cards from the
top of your library until you reveal a creature
card with converted mana cost 3 or less and put
it onto the battlefield, put the revealed cards on
the bottom of your library in a random order, if
you're playing for planechase, roll the planar die,
if you planeswalk this way, transform Yienva.