In the Rengar Champion Spotlight, you’ll learn how to prowl the jungle and engage your enemies as you follow our resident champion expert, Phreak, on a ruthless hunt with the Pridestalker. On every wall of his den, the trophy hunter Rengar mounts the heads, horns, claws, and fangs of the most lethal creatures in Valoran. Though his collection is extensive, he remains unsatisfied, tirelessly seeking greater game. He takes time with every kill, studying his prey, learning, and preparing himself for the next encounter with the one monster he never managed to defeat.



Unseen Predator (Passive): While in brush or stealth, Rengar will leap at the target when using his basic attack. Rengar builds 1 Ferocity with each ability he uses on enemies. When reaching 5 Ferocity, Rengar's next ability becomes empowered, granting it a bonus effect.

Savagery: Rengar's next basic attack deals bonus damage and grants him increased Attack Speed for a short duration.
Ferocity Bonus: Rengar deals enhanced damage and his Attack Speed bonus increases.

Battle Roar: Rengar lets out a battle roar, damaging enemies and gaining bonus Armor and Magic Resist for a short duration.
Ferocity Bonus: Rengar heals himself for a large amount.

Bola Strike: Rengar throws a bola at his target, slowing them for a short duration.
Ferocity Bonus: Rengar roots the target.

Thrill of the Hunt (Ultimate): Rengar activates his predatory instincts, stealthing and revealing all enemy champions in a large radius around him. He gains Movement Speed and rapidly generates Ferocity while stealthed.



Source:
http://na.leagueoflegends.com/news/c...r-pridestalker