Rengar is an assassin type jungler with some insane burst potential due to his Q + E combo, after level 6 his ganks can become the most deadliest in the game, his ferocity E is 9/10 a kill secured. Use his ult to catch out their carries in early and late game and watch your team win.

Start Red or blue dependant on which is bot side (for the better pull) and head to wolves then to your other buff. You can invade their buff after you get your red and wait for them in a bush then pounce on them for an early first blood/free buff.

Rengar jungle is your very average jungle experience however his early level burst potential, slow/root, and ult makes him a much more viable pick to other champions.
- When clearing your jungle make sure when you have the option to use ferocity that you use your Q as the damage burst and attack speed boost are much better than the W heal which will most likely run out by the time you have finished clearling the camp. -
You can play Rengar two ways - The first blood way which you will play very aggressively and counter jungle/gank early and get a free kill. - OR you can play the passive farm to level 6 way which is how i like to play him. Either way you should try to gank mid at level 6 to set your mid laner into the lead and in a position to carry.