Shivsnab, Yidris' Cohort

Deathtouch, Skulk
Whenever Shivsnab, Yidris' Cohort attacks
and isn't blocked, exile it and the top four cards
of your library in a face-down pile, shuffle that
pile, then an opponent of your choice chooses
one of those cards. Look at it. If the chosen card
is Shivsnab, put that card onto the battlefield
face up and shuffle the rest of the pile into your library. Otherwise, entrap that card and repeat
this process.