Heavy split-push and healing.
Durability and crowd control
Every 4s your next attack on a champion deals bonus damage, heals you, and permanently increases your health.
Charge up a powerful attack against a tower while near it.
Gain 5 Armor. Whenever you heal for at least 20 health or from a consumable's effect, increase your Armor by 5% for 3 seconds.
Heals and shields are 5% stronger and increased by an additional 10% on targets below 40% health.
+65 health and +9% attack speed
Takedowns on enemies grant permanent Attack Speed.
Takedowns restore health and grant bonus gold.
Trundle is one of the best users of Grasp thanks to his innate auto-attack based kit and stickyness with [Q] and [E].
If left alone Trundle is one of the fastest split-pushers. [Q] + Demolish means you'll be cutting down towers in no time.
If you're looking to teamfight rather than split-push, take Font of Life instead.
The early armor from Iron skin lets your take trades early and heal off any damage with your passive.
Take Mirror Shell here if you're against a heavy Magic damage comp, or Conditioning if you want to be greedy for the mid-game.
Revitalize synergizes incredibly well with Trundle's natural healing from his passive and [R]. It also synergizes well with Font of Life and Overheal.
Trundle could always use more auto-attacks and this is your only source of Attack Speed.
If you're intending to build a lot of AS (like BotrK) you could take Legend: Tenacity instead.
Triumph empowers your ability to absorb massive amounts of damage in teamfights with your ability to pick up kills/assists and heal form your passive + Triumph.