At the intel masters UOL used to be the underdog vs TSM. In the End they knocked TSM down in just 2 crazy games. The second game they just played better but the first game was kind of special. They baited Bjergsen to pick Xerath against a TF midlane. Actually this TF was a jungle pick and Power of Evil destroyed Bjergsen with Le Blanc in lane. I thougt TF jungle is really cool so i tried it out... and its legit!

pros:
very good ganks early lvls
your everywhere after lvl 6
dragon control with ult
good late game
hybrid- and damage per second

cons:
slow clear early lvls
take much dmg if u dont kite the jungle creeps
easy to counter jungle
squishy (you need a fitting team composition: Gnar top etc.)

I start at Blue go to woves and than do red. Smiting red will restore most of your hp so you can gank with full hp at lvl 3. You need to find a position to kite the monsters. Ranged champions can stand in a position that allows you to attack the monsters but the monsters cant attack you and will just walk to you and back to their camp all the time. That make you take less dmg of the jungle but also slows your clear slightly. Care with the Gromp! YOu cant muck arround with that guy. After you Devourer jungling is a lot easier.

If u gank lanes allways watch out that the laner cant turn on you. Also counter ganks are deadly! You should have your stacked deck ready for a good burst dmg. If u hit the gold card and your laner is following it is usually a free flash or a kill you can get!
After lvl 6 focus on midlane and use your ult for botlane. If u manage to get a kill botlane or midlane that gives you a chance to get a free first dragon!