Promethean Crawler

"These are Crawlers - fast and mean, but pretty easy to deal with."

- Jared Miller describing Crawlers to Fireteam Crimson.

The Crawler is an autonomous Forerunner defense construct, serving as part of the Ur-Didact's mechanical Promethean army as a means of asymmetrically combating the Flood.

Overview
Crawlers are small, quadrupedal machines capable of both ranged and close-quarters combat, using a built-in Boltshot as their primary weapon; this weapon disintegrates targets to prevent their biomass from being co-opted by the Flood. Unlike the majority of Forerunner automatons, they lack anti-gravity capabilities of any kind and instead rely on their four legs for locomotion. They are however capable of vertically scaling structures in order to get tactical advantage. Crawlers are ferociously aggressive, having been specifically designed to hunt down and eliminate any foreign threats, their inorganic nature making them immune to Flood infection. They travel in large packs and work together to destroy enemies by overwhelming them from every conceivable angle, relying on skirmishing tactics.

Crawlers are often directed by Promethean Knights, who regard them as cannon fodder. They are protected by Watcher Sentinels, which can offer them cover in the form of small hardlight shields or create new Crawlers from raw materials in the ground. In addition to the basic type of Crawler, a more heavily armed unit and a long-range unit are also employed.

It is unknown for what purpose the Ur-Didact originally used Crawlers for. It has been theorized they were sent into Flood strongholds to soften their infantry numbers before more valuable assets were sent in. Numerous Crawlers were encountered by UNSC Defense Force and Covenant personnel on the shield world Requiem in mid 2557.

Subtypes

 * Crawler Snipe - a further upgraded long-range Crawler variant with a built-in Binary Rifle.
 * Alpha Crawler - a variant which leads packs of lesser Crawlers and utilizes a Suppressor in combat.

Trivia
Promethean forces were named for chess game pieces during Halo 4's development. The Crawler was originally called the Pawn. It remains the character model's file name in the game code. Only the Knight retains its chess piece name.

List of appearances

 * Halo 4
 * Spartan Ops
 * Halo: Escalation