The new official Clone Wars timeline has not yet been established by Lucasfilm. The exact chronology of the events described in this article is currently unknown.
The tri-droid was an up-scaled version of the smaller octuptarra combat tri-droid. The Techno Union developed the combat version first, re-using the design later for the much larger heavy artillery version of an infantry battle droid.
Chain-fed ordnance launchers replaced the laser cannons of its predecessors, with the reserves of ammunition stored within the hollows of its bulbous head, although some models did retain laser cannons as seen in the Battle of Christophsis. One rocket fired from a single behemoth was powerful enough to annihilate a UT-AT if aimed correctly, as seen in the Battle of Mygeeto. These three-legged artillery droids were formidable in battle, reducing infantry and tanks to rubble. Their rotating multi-jointed assemblies allowed them to change facing almost instantly and they could fire from extended ranges. It was almost impossible to approach such droids, as all sides conceivably faced the front. The droid was also capable of hanging onto vertical surfaces, as seen during the Battle of Christophsis.[4]
Prior to the battle, Asajj Ventress used one of the droids to escape from Generals Kenobi and Skywalker. The droid was destroyed when it crashed to the ground from the building it was clung to, thanks to the 2 Jedi severing it's limbs.
The Databank gives the height of the tri-droid as 3.7 meters, which is incorrect, as all visual sources portray it as many times larger than a Human, and even the same Databank entry describes it as "gigantic" compared to the 3.6 meter octuptarra droid. The decoded episode of "The Hidden Enemy" was the first source that gave tri-droid's height as 50 feet tall.