The Gorkanaut is a large, heavily armed walker created by the Mekboyz and piloted into battle by a lone Nob. Much larger than a Deff Dred, it is essentially a small Stompa. It sports a myriad of heavy weapons, including two Twin Big Shootas, a Deffstorm Mega-Shoota, two Rokkit Launchas, a Skorcha, and a Klaw of Gork (or possibly Mork). The Gorkanaut is a brutal engine of destruction that serves as a living avatar of Gork upon the battlefield.
In 8th edition the Gorkanaut is pretty resilient with T8, 18 wounds, and a 3+ save. It is primarily an infantry wrecker. The Deffstorm Mega-Shoota (a gatling gatling gun) pumps out a whopping 18 strength 6 ap-1 shots a turn and can reduce an entire tide of GEQ's into a fine meaty paste. This loadout is very nice on the overwatch, with lots of dakka being supported by a Skorcha. The Klaw of Gork (or possibly Mork) can either be used to perform a Crush with 6 attacks at strength 16, ap-4, and D6 wounds per hit, or it can perform a Smash with an insane 18 attacks at strength 8, ap-2, and two wounds per hit. Either way, the Gorkanaut will shred most things that are foolish enough to engage it in melee. It also has a 6-Ork transport capacity with no assault vehicle or firing points for...reasons, so don't use it to transport anything that wants to assault or shoot.
A Gorkanaut (or two, or three) makes an excellent DISTRACTION CARNIFEX due to its firepower, toughness, intimidating size, and overall meganess. Your opponents cannot simply ignore it, and if they do, you'll have the ability to obliterate anything you get near.
The Gorkanaut's brother is, of course, the Morkanaut.