Yes, _that_ game.
Rengar is a hunter, through and through. The thrill of the hunt pushes him to track down and eliminate the most fearsome creatures known to Runeterra, often without regard for his own safety. This desire to hunt is so prevalent, it rivals the inherent need to feed of his most recent quarry, Kha'Zix. So long as his prey provides a sufficient challenge, Rengar will gladly carve from them a trophy to commemorate his mastery of the hunt.
However, Rengar has found less and less worthy prey, with only Voidreaver proving to be a difficult, and dangerous, catch. When beasts of Valoran fail to satisfy his love of hunting, to what will the Pridestalker turn to in his need for a good kill?
In "The Most Dangerous Game" a short story by Richard Connell, a man by the name of Sanger Rainsford falls off a ship traveling to Brazil and swims to an island notorious for its propensity to wreck ships. There he discovers a general by the name of Zaroff, a hunter who became dissatisfied with hunting after the world's various creatures failed to offer him a sufficient challenge. On this island, briefly home to stranded sailors, Zaroff pursues the most dangerous game of all: man.
While there is no explicit evidence to support the belief, most assume Rengar inhabits or at least hunts primarily in the Kumungu jungles. With the release of Rek'Sai and Ekko's supplemental material, we know that members of the various nations travel beyond the limits of their countries' borders; Noxian trappers, wealthy Piltover aristocrats, traders from Shurima, they could all venture into the Kumungu jungles to fulfill personal agendas.
Foreigners that enter the treacherous lands of Kumungu may qualify as an open invitation. Numerous parties could enter the unforgiving forests with varying degrees of preparation, providing a unique test for Rengar with every guest. The question remains: would Rengar hunt humans?