Squiggoth
The Squiggoth is a particular breed of Squig that grows to massive proportions. Orks with a particularly low-tek bent, such as Feral Orks and the Snakebite clan, make use of them as transports and/or heavy artillery embankments, steering the monstrous multi-ton quasi-dinosaur beasts into the enemy. Covered in ramshackle armor, bristling with turrets manned by desperate grots and more than willing to trample, gore, crush or eat anything in sight, squiggoths are surprisingly effective.
It also shows the biological rivalry between the Tyranids and Orks as each species tries to one-up each other on who can be the biggest and strongest.
Though they haven't been seen in ork army lists since Chapter Approved did its entry on Feral Orks, they have retained notability by being the ork Relic Unit in Dawn of War.
There are three recognized sub-species of Squiggoths.
Big Squiggoths
The smallest (Though still quite large) and most common variety of Squiggoths. Big Squiggoths stand about the size of a Leman Russ tank or a Elephant. Their smaller size is the result of either youth or the poor breeding methods of their Ork caretakers. They often travel in packs, particularly on worlds dominated by Feral Orks.
Either way, they are still large and powerful enough to smack light and medium vehicles like tin cans and devour entire Space Marines if given the appropriate chance and mood of these beasts of burden.
Gargantuan Squiggoth
Gargantuan Squiggoths are monstrous creatures approximately the size of a small Imperial Titan. Their size is the result of their breeding using the special, high-quality feed formula of the Snakebites Clan. These giants are sometimes used as mounts by the most powerful of Ork Warbosses. This is the variety seen in the Dawn of War games and it is by far the more recognizable of all Squiggoth types.
Their charge is powerful enough to break fortifications and cause a severe case of Squad Broken as well as potential Rage. They are also potentially big enough to give the Hierophant the middle finger before tail slapping the overgrown tick into submission.
Orkeosaurus
Orkeosaurus is the largest breed of Squiggoth that is used by the Orks. Looking more like a Dinosaurine Sauropod than the elephantine looks of its smaller brethren. The Orkeosaurus is larger than all other Squiggoths, including the Gargantuan Squiggoth.
The Orkeosaurus is usually found amongst Feral Ork tribes and is rarely, if ever, seen in use by the more technologically advanced Ork klanz. The massive creature is used as both a beast of burden and as a beast of war by the Feral Orks and the Orkeosaurus is highly valued not just for the carnage it can cause in battle but also for the prestige that it can bring to the Greenskin tribe that possesses one. When the tribe marches off to war they are accompanied by the trumpeting calls and the thunderous tread of their mighty Squiggoths and Orkeosauruses.
In Dawn of War
The Big Squig isn't the most destructive thing around (those honors go to the Baneblade and Bloodthirster) neither is it the fastest (Also, since it's so fat, it's prone to getting stuck in your base if you built Da Mek Shop in the back). It could almost be called a Land Raider with a mouth fulla teef an' stompin' feet, since it has two slots of transport capacity for Boyz getting stuck in. As you can imagine, this makes for incredible versatility, not in smashing things, but in dumping a threat straight on the opponent's head, and having another threat pop right out. Rampage helps a lot with this, as well as making those puny otha gits fly errywhere and clearin' a path fer da WAAAGH!