This is my first build, I decided to do trundle because after the rework his potential is limitless, since the rework I have personally played many games as trundle, and as im writing this I remain at 100% win rate as Trundle with this build.

With the rework trundle was reborn as "The Troll King" of the Freljord, this rework included a variety of buffs and slight nerfs. Trundles CC potential has grown with the addition of a 75% slow for 0.1 second on his Q, which doesn't sound like a lot, but seeing as how spammable this ability can be it is very effective at chasing down enemies. Trundles Ultimate has been reworked into being more noticeable in team fights as a damage/drain ability which does 24-25% max hp as damage, combo'ed with BOTRK in this build allows for a tanky trundle that also deals massive percent damage. The nerf that hit Trundle was the time the pillar was up, reduced by one second.

Trundle was quite easy to kite before his rework, but now with the item builds capable to reducing speed, and increasing trundles he can 1v1 almost any champion in my experience, and is now a master of chasing down fleeing enemies.

Pros:

Massive early game damage.
Good early ganks with pillar.
Percent damage.
Fast and health/mana efficient clear.
As of the rework Trundle can now interrupt channeling spells with pillar.

Cons:

Damage falls of late game.
Can Be kited (build to reduce this)
No hard crowd control
People call you a troll. ;)

Starting the game:
At the start of the game your goal is to clear the jungle as fast as possible, while keeping at a relatively high health points to allow ganks to occur.

As Trundle I usually like to start with wolves and then get a smiteless blue if possible, then go clear wraiths and smite the redbuff down then gank top if purple side, or gank mid if blue side. (this process can be reversed to gank the opposite lane for each team.) At this point you should be level 3 and have both buffs, and skill points in Q,W,E to allow for a successful gank.

Ganking:
Trundle is an extremely good ganker, especially in the early levels. As a level 3 you have the ability to speed yourself up, slow the enemy, and block their escape with pillar.

I know many people will think this is obvious but i would rather cover all bases possible for those who might not know. However, as any Jungler before you gank you should check the item inventories of the person/persons you are about to gank, for example if i'm ganking a Garen Top and he has 5 health pots, and a cloth armor then he doesn't have a ward. Therefore the ganking paths can be through the river, tri-bush, or lane depending on their position in lane.

For ganking bot lane, if my team has not pink warded and their team isn't extremely over extended I like to either try for a lane gank and make my way into a lane bush (ask your team if it is warded or not) or this is a perfect time to use your ghost which combo'd with your W will most of the time reward your team in a kill.

Team Fighting:
Okay as Trundle, depending on how fed you are you can perform differen't roles within a team fight, as a tank you should be in the front line either initiating, or counter initiating. This is where your role will differ depending on how well you, and your team is doing.

If you are doing well as trundle, it is extremely easy to blow up one of the carries with the 20-26% HP/armor drain from your ultimate + the 15% from your BOTRK. From this you will basically reduce the other teams damage from preventing a carry from focusing a crucial target.

Later in the game your damage will be less substantial, however you can still disable one of the carries, however what may be better to do in certain situations is to peel for your ADC will pillars, BOTRK active, and Q slows.

Trundle is an Anti-Tank Tank, I know this sounds stupid but if you ultimate a tank for the % damage you will be able to do much more damage to them, and also get much more tankier yourself because most tanks have more hp/armor than any of the crucial targets.

If you guys want me to post your scores, good or not, with this build please send them to me ill be more than happy to pose them as proof to this build =D.

Thanks for taking an interest in my build, if there are ANY parts of Trundle gameplay you want me to go over, just ask so in the comments and I do my best to answer the question, and add it to the guide. This Guide is not complete I will be adding more information to make this the best and most informative Trundle build.

Thanks- Execl.