Changes

|'''[[Catachan IV, V, & VI]] |''Headhunters''|It took part in the [[Macharian Crusade]], but was wiped out during the [[Invasion of Jucha]].{{Fn|6}} The [[Regiment]] was later refounded and then took part in the [[Invasion: Verdicon]] against [[Hive Fleet Kraken]] on [[Verdicon]].{{Fn|38}}

|-|'''Catachan V & VI'''||The Catachan 4th, 5th, and 6th took part in the [[Macharian Crusade]] alongside the [[Catachan IV|4th]] [[Regiment]] and all had varying success. The 4th was wiped out during the [[Invasion of Jucha]] while the 5th only met fierce resistance. The 6th ''(Cobras)''{{Fn|6}} were notably deployed from the [[Battlecruiser]] [[Opus Dei]].{{Fn|4a}}

|The Catachan 18th fought [[Tyranid]]s in a seven year campaign on [[Koralkal VIII]], during which they covered themselves with the ichor of the [[Lictor]]s to mask their scent. They subsequently spent two years in decontamination before they were allowed to return to active duty. A notable member is [[Colonel]] [[Gator]].{{Fn|1b}} Also in this campaign regiment the Regiment used [[Tarantula]] sentry guns.{{Fn|3g}} They also have a [[Thunderer Siege Tank]] as part of their forces.{{Fn|3a}} Took part in [[Invasion: Verdicon]] against [[Hive Fleet Kraken]].{{Fn|38}}

|''Constrictors''|The Catachan 23rd were crucial during the conquest of [[Atria IV]], as their elite sapper units were able to breach the [[Palace of Hate]] within a week.{{Fn|1d}} They took part in [[Invasion: Verdicon]] against [[Hive Fleet Kraken]].{{Fn|38}} The Regiment also fought on an unstated jungle world [[Jungle World]] against the [[Eldar]]. In 981.[[M41]] while isolated on the [[Agri World]] of [[Lowamon]] after three years of bitter fighting, [[Colonel]] [[Kratzer]] and [[Inquisitor]] [[Roth]] rally the Catachan XXIII for one last defiant stand against [[Tau Commander]] [[Darktide (Tau Commander)|Darktide's]] [[Mont'ka]] assault.{{Fn|13}}