Once hes summoned, you get to amass a five-strong Orc army, and mill five cards to the graveyard, then choose one creature card from that lot to play immediately on the battlefield, with no need to pay the Land cost
This flexible ability can be used both offensively and defensively, as when on your turn, it can prevent attacking Merfolk from being blocked by creatures of a given color
That can't be it
Hexproof addressed that issue but created its own: piling a bunch of improvements onto the same creature that an opponent can't interact with
If I recall correctly, this began in the core set with Garruk, Primal Hunter with a rough five-cost with triple Green, but then +1 to make a 3/3 Beast that's Green or -3 once to draw
Payout is 70% of the total entry fees to Top Cut in typical deviation