The Knight Errant pattern Imperial Knight armoured walker is a mainstay of many knightly houses. Of the varied types of Imperial Knight seen upon the battlefields of the 41st Millennium, the Knight Errant is best known as a devastating, close-ranged killer -- a tank-hunter extraordinaire. Many an enemy vehicle has been quickly melted to no more than hissing piles of molten slag by the Thermal Cannon slung underneath a Knight Errant's mighty shoulder. Once a foe is sighted, a Knight Errant typically seeks to close the distance -- firing off hissing blasts from its Thermal Cannon as its great strides propel the walker rapidly forward. Thanks to their size, thick adamantium armour and directional Ion Shield, Knights Errant do not hesitate to charge straight into the teeth of the enemy's most potent weapons. Once amongst its foes, a lone Knight Errant can best an entire tank battalion, shooting and stabbing its way through their formation to leave only twisted ruin and blackened hulls in its wake. The Knight Errant's close combat weapon -- either a Reaper Chainsword or Thunderstrike Gauntlet -- is perhaps more deadly still. When powered by the Knight's mighty servo-engines, either of these weapons can topple even the most monstrous xenos creature with a single strike. Fitted into the Knight Errant's armoured carapace is a Heavy Stubber to scythe down enemy infantry, and its armour-plated feet are more than capable of crushing units beneath its awesome weight.
Based on the same ancient frame as the Knight Paladin armour, the Errant mark armour mounts an imposing Thermal Cannon in place of a Rapid-Fire Battle Cannon. This terrifying weapon is more than capable of vaporising even the most resilient of armour in an instant. Most often employed to hunt down and destroy enemy super-heavy monstrous xenos creatures, Errant mark armours are usually assigned to the more aggressive scions, and in turn armour themselves often develop a belligerent anima. Few Errant armours carry the long lineage of many Paladin Knights, as only the most skilled survive for long, though such armours often carry with them a collection of battle honours that few others can match. Some of the oldest Errant armours, veterans of many lifetimes of battle, are so fractious of spirit and spiteful of temperament that only the most iron-willed of scions can master them, bending their bloody instincts to the service of the Household.
In the 41st Millennium, the Knight Errant is a mainstay of many knightly houses. The strengths of the Knight suit are perfectly matched by the aggressive, charge-the-foe nature of its pilots. Knights Errant often spearhead attacks, and by a battle's end they will have smashed and carved their bloody way into the very thickest of the fighting. Even protected by their armour and Ion Shield, battle damage is common for such venerable engines of war. After each action, the hulking giants are literally crawling with Sacristans, for most knightly households uphold the tradition that post-battle a Knight should not be seen with so much as a single scratch upon its livery. The ancient machines are lovingly cared for, with attention paid to every armour plate and sacred unguents lavished upon every cog. No less scrutiny is spent ensuring that the Knight’s personal heraldry is likewise maintained, for the symbols it incorporates proclaim everything that a Noble takes pride in, including his home world, house, oaths, rank and his most lauded battle honours.
- Codex: Imperial Knights (7th Edition) (Digital Edition), pp. 9, 11, 20, 26, 31, 38-40, 42-43, 46, 49, 55-56, 58, 60, 67, 71, 74-76, 79-80, 83-84, 88-89, 93, 96, 99, 102
- Codex: Imperial Knights (6th Edition) (Digital Edition), pp. 3, 9-10, 135-136
- The Horus Heresy - Book Four: Conquest by Alan Bligh, pg. 302
- The Imperial Knight Companion (6th Edition), pp. 17, 24-25, 28-29, 31, 36, 42, 48, 52, 56, 62, 64-66, 70, 72, 78-79, 86, 88, 92, 94, 98, 124, 126-129, 138, 142
- White Dwarf Weekly Issue #66 (02, May 2015), "Regiments of Renown," pg. 78
- White Dwarf Weekly Issue #23 (05, July 2014), "Knights of the Household," "Designer Notes," pp. 48, 50, 59-60
- White Dwarf Weekly Issue #7 (15, March 2014), "Joining the Crusade," "The Rules - Apocalypse Datasheet," pp. 19, 22, 50-51, 59-60
- White Dwarf Weekly Issue #5 (01, March 2014), "Imperial Knights," "The Imperial Knights Companion," "House and Heraldry," "Creating Your Own Freeblade," "Hold the Line!," "Paint Splatter," pp. 3, 10, 19, 23, 28, 30, 32, 40, 44, 50, 64
- White Dwarf Weekly Issue #4 (22, Feb 2014), "Imperial Knight," "The Rules - Imperial Knights," pp. 9, 56-58