This is my first build so feedback is always welcome. I decided to make a build for trundle because I haven't really found an incredibly good build for him yet. Several builds have trundle being built as dps/carry, some have him as a tank, and others as an offtank. I personally feel that trundle as an offtank is hands-down the best way to build him. So lets get started.

--EDIT-- 10/20/2011
COMPLETE REVAMP OF GUIDE. Decided I like laning trundle solo top bcs its just too easy. Might eventually remake the rest of the guide, but for now i just thought i'd post the items for solo top trundle.

--EDIT-- 2/26/2012
Just fixed up the masteries, sorry about the delayed update; I was in basic training for the airforce and didn't really get a chance to update this -_- build still kicks butt in the game. I know this for a fact cosidering I've been away from LoL for a while (obviously) and still come back and use this same guide to completely dominate :) also tossed in deso quints as an option and changed summoner spells to ignite/flash from ghost/flash simply because ignite+rabid bite=ks (kill secured) ;)

Trolls have never been well-regarded beings of Valoran. Generally speaking, they are barbaric, cannibalistic, and sneaky. They are creatures relegated to the murky recesses of the world, hidden away from most intelligent beings. Despite their maleficent natures, however, the Ruhgosk never deserved the grisly fate that was visited upon them. Generations ago, a twisted necromancer known as Hakolin the Bonecrafter attempted to enslave the Ruhgosk tribe. These trolls are considerably more genteel than their ill-mannered brethren, although still uncouth by human standards. The Ruhgosk fought tooth and claw against the necromancer, ultimately driving him from their land. As a parting gift, Hakolin afflicted the trolls with a leprous disease, forever cursing the members of the tribe. The leprosy would have rotted their flesh away to nothing were it not for the trolls' natural ability to regenerate. Caught forever in a hideous rotting state, the Ruhgosk endured their curse while desperately in search of a cure. They never found one.

A wise Ruhgosk shaman learned that he could magically bind the disease to a single troll, provided that the troll could bear the weight of the entire tribe's curse upon himself. However, there was no such troll...until the birth of Trundle. His ability to regenerate was so profound that it appeared as if he did not carry the disease. As Trundle grew, he came to understand his gift and what it could do for his people. When he came of age, he took the curse from his tribe in a baptism of searing agony. Through the shaman's ritual, Trundle became a horrifying creature whose flesh constantly sloughs off his body, only to be re-grown in an unremitting cycle. He has joined the League of Legends in hopes of eventually finding someone who could dispel the heinous curse completely.

''I've learned a thing or two about pain! Let me show you.''

- Trundle

these items make trundle super tanking while at the same time being able to shut down both the ad carry with his rabid bite, and also make the tank rethink his idea of actually tanking with agony

i know alot of you are thinking "wtf?? utility tree on trundle?????" trust me, its freaking awesome when laning as him. you can use rabid bite whenever you have to last hit 2 minions in a row and not have to worry about your mana pool getting low. the movement speed mastery ontop of contaminate and movement quints garuntee you can catch up to any enemy and knock them back with pillar of filth

Pillar before contaminate just incase of lvl 2 gank (against you or for you, either way the pillar will stop them if placed correctly)

you can make or break trundle with your pillars alone. they are super effective in stopping enemy hero from chasing or from running away. if they are running away, look at the direction they are going and place your pillar right on their nose or slightly infront. if done correctly you will actually push them bak towards you, and the slow from pillar of filth at that point makes it a complete snare (ive even placed a pillar a couple times where it glitched and the enemy champ couldn't even move until the pillar was completely gone, teehee dont tell riot). if they are chasing you or your teammate, just simply put it right inbetween the enemy and the ally or ureself. also if done correctly, you can completely rip the enemy off you or ure ally. epik pillarz are epik

look, i know you want to pop agony on the enemy team's epik crazy good carry, but if you team is simply focussing that carry super hard every team fight and that carry isnt carrying, then dont waste your ult. you are better of using it on a tank, or the 2nd carry or jungler to melt them down fast as well and make you have stats of a tank but deal damage like a carry. just sayin... don't waste the ult, its too good to be wasted

Pillar of Filth reveals fog of war.

Rabid Bite will miss if Trundle is blinded.

Rabid Bite will be blocked by, and remove spell shields such as Banshee's Veil.

Trundle excels at fighting within his Contaminate zone. Try to draw enemies onto it.

Use Agony to soften a powerful enemy tank or to create a target for your team to focus fire.

Rabid Bite is good for lowering the physical damage of enemies; try to focus it on enemy physical damage dealers.

http://na.leagueoflegends.com/champions/48/trundle_the_cursed_troll
http://leagueoflegends.wikia.com/wiki/Trundle_the_Cursed_Troll

In Summary: Don't hate the player, hate the club that's smashing your face in.

Please leave constructive feedback :D