Kathari Remnant

Kathari Remnant {2}{U}{B}

Creature - Bird Skeleton | Power/Toughness: 0 / 1 (CMC 4)
{B}: Regenerate Kathari Remnant.
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)