Enki

Enki (エンキ?) is Viral's personal Gunman, modeled after an armored samurai. The Enki is the product of significant innovation in Gunmen technology, and sports a number of advances that eclipse lesser models in performance, and is the first model seen to support solid-based ammunition. Unlike stout Gunmen, such as the Gurren, that have bulky limbs that can only be used in wide swings, the Enki is more segmented and has multiple joints that allow it to perform complex actions, such as throws, kicks, and various martial arts techniques. The Enki's arm and thigh plates conceal rows of hidden gun turrets that fire large steel projectiles (kunai). There are pop-up compartments in the shoulders that can fire a single volley of rockets, and the entire chest plate can open to reveal a number of launchers that deliver an explosive payload of missiles. The Enki possesses a wrist mounted concave blast-shield, and a helmet with a large black ring atop of it, that is actually the charging focus for a medium-range particle beam cannon. Its helmet becomes the possession of Simon and Kamina, as they stole it/ripped it off when they first combined to make the Gurren-Lagann.

Viral's Enki bears striking resemblance to Vanguard Bandits' ATAC named #69.

Enkidu
Later, the helmet-less Enki has been redeployed as the degraded "Enkidu" (エンキドゥ?) and sports a new sickle-like weapon, which is affixed to its head (a homage to Ultraseven's Eye Slugger weapon). When wielded, it provides an alternative to the dual swords the Enki usually resorts to in melee combat. Furthermore, it is also capable of shelling from afar by physically launching munitions from the same point on its head, once the sickle has been removed. When it is aided by Cytomander's air raid on the Dai-Gurren, it was also equipped with a flight engine, allowing it to fly.

Enkidudu
During the Invasion of Teppelin, Viral's Gunmen remodeled into the "Enkidudu" (エンキドゥドゥ?), replacing the sickle crest for an extra pair of arms, meaning the Gunmen can now fight with four blades. When the new form fights the Gurren-Lagann, however, it is swiftly defeated, despite its upgrade. After the timeskip, the Enkidudu is shown fighting the Grapearl unit, in order to protect a group of humans who decided to continue living underground. However, the damaged Enkidudu is unable to hold its own against the advanced Grapearls and is ultimately defeated, shutting down as Viral thanked his mecha for lasting this long for his grudge. The fate of the Enkidudu is never known, but is likely scrapped like the other Gunmen.

Etymology
All forms are based on figures in Sumerian myth: Enki was a god of wisdom. Enkidu, meanwhile, was the wild man who fought and befriended King Gilgamesh during the Sumerian epic. The latter seems to bear significance to Viral's role in later episodes. It is possible that the mecha's name is a reference to French comic author Enki Bilal as Viral can also be read "Bilal" in Japanese. This is further evidenced by the title of Viral's theme, "Nikopol", which is the name of one of Enki Bilal's most famous work, the Nikopol Trilogy.

Trivia

 * In the Drama CD, the upgrades were made into running joke in the form of the six-armed and tailed "Enkidududu" (エンキドゥドゥドゥ?), and the "Enkidudududu" (エンキドゥドゥドゥドゥ?), which resembled the Enki with eight arms, two tails, a cat-like head on the shoulders, and unique configuration into a giant dragon head.