Neat-O Renekton Jungle Build
I've had some success so I felt like sharing. 
How It Works:
- Start at Krugs, learn Ruthless Predator first. With Ruthless Predator you get multiple procs of the Krugs buff!
- Smite Krug, 2 AAs, immediately W, then 2 more AAs. Stunned 3 times in under 5 seconds.
- Stay at under half HP as you jungle so you can use Renekton's passive. Lol.
- Avoid the chickens until level 4+ as they will certainly be your demise.
- Gank. A lot. Whenever you think you should. This is the best thing about Renekton jungle: Immediate hard CC and 2 dashes. Doneski with any competent laner.
- You secure every dragon with empowered W + Smite. Pretty much only beaten by Nunu's dragon/baron secure.
- You chop half of the other jungler's HP bar off, essentially immediately, guaranteed, whenever you tussle during laning phase.
Runes: 9 AD Marks, 9 Armor Seals, 6 MR Glyphs, 3 MR/lv Glyphs, 3 AS quints
- works really well!
AS quints because:
- More fury is great
- Strong start against Krugs and against the jungle in general
- AD doesn't scale (hue) on him past the first few levels
- You can probably pull off not having them, though. They just seem more valuable to me than more flat AD or even arpen.
Masteries: 10/17/3 Perseverance because you'll (typically intentionally) have a lot of missing HP while you jungle 1.5% MS because you'll be moving around a lot Runic Blessing because* it's a jungle out there*
First Items: Stalker's Blade - Warrior - because it's OP Ranger's Thingy - Warrior - because you don't have a lead yet and need the sustain (Smite THEN Q, when finishing off creeps) BoM - EZPZ Ganks. WARNING: Don't push lanes alone with these boots because you will get caught and killed. Sell for whatever other boots you want lategame Tabi/Treads - quality boots for boring laners Brutalizer - obnoxious damage once you have the Warrior enchantment
y'all don't have too much fun now, ya hear?