Deepfathom Explorer

Whenever Deepfathom Explorer attacks, defending player may pay {2}. If he or she doesn't, Deepfathom Explorer is unblockable until end of
turn.
Whenever Deepfathom Explorer deals combat damage to a player, look at the top five cards of
that player's library. Then you may put them
back on the top or bottom of that player's library
in any order.