Armageddon Ork Hunters
To sum these guys up, you need to first take the Catachan Jungle Fighters and..
- Make them less swole and giant. (Don't worry, dey still swole doh)
- Replace growing up on the galaxy's deadliest planet with surviving regiment-wide destruction by Orks.
- Swap Catachan Knives for "Scalper" Machetes.
- Add in a fetish for wearing scraps of Ork armour and bones.
- Give them a crazy, fuckhuge base in the middle of an Ork infested jungle.
- Give them an unquenchable need to fuck up Orks.
With all this, you get the Armageddon Ork Hunters. Basically, they are as close as a normal human can get to being a Catachan, which is actually pretty badass considering those guys are giant Ogryn-like badasses. These guys (if you haven't guessed by now) really love killing Orks... seriously, like... a lot. This is due to the fact that the Ork Hunters are made up of survivors from other regiments who were wiped out by Orks during the 2nd and 3rd wars for Armageddon. Whilst most of these guys are ex Steel Legion, many others come from various IG Regiments who helped defend Armageddon against Ghazghkull and his cronies. This process of recruitment means only the toughest and most badass of soldiers can get in. Whilst they could just be sent to another of their native regiments, their sheer badassery and newly forged hate-boner for Orks, means that they are considered far more useful being dropped into Armageddon's jungle.
Ork Hunters have only been around since the 2nd War for Armageddon, which means they are a pretty young regiment compared most others. Despite this, the Ork Hunters, due to being badass Ork murderers, have already gained an elite and brutal reputation. They operate out of Cerbera Base, a stronghold that is bang splat in the middle of Armageddon's Equatorial Jungles, surrounded on all sides by hordes of Feral Orks. From here they wage a constant war against a musclebound alien species that loves to fight and feels no pain... and proceed to fuck them up. Ork Hunters are known for looting Ork corpses for weapons and armour, some even wield Sluggas rather than standard Lasguns. The most elite Ork Hunters, who comprise badass Firesweep Teams, wield heavy Ork Choppas in melee combat. In addition to their normal equipment every Ork Hunter also carries a 'Scalper', a huge fuck off machete that can be used to decapitate an Ork with one blow.
The Ork Hunters not only hunt Orks. When initially brought to Cerbera they are trained in various different methods of warfare, including demolition, escape and evasion, survival and intelligence work. Ork Hunters are expected to become masters of their weapons and techniques, and those who survive (yes, even badass sole-survivors end up dying trying to join the Ork Hunters) receive the metal pin of the Ork Hunters, an Ork Skull emblem. From this they have derived their nickname, the 'Skull Takers', which is also attributed to them collecting Ork skulls as trophies. Nice.
At the end of the day, whilst still not being as good as the Catachans, these guys are still better than your average Guardsman, literally being made up of the toughest and most survivable of regiments like the Steel Legion, Death Korps of Krieg, and countless others who have fought on Armageddon. Aesthetically, they look more like Arnie at the end of Predator than they do Sly in Rambo, which also appeals a lot to certain players who want a different kind of jungle fighter. The tendancy of Ork hunters to wear orkish armor and use orkish weapons also gives them an ironic resemblance to loyalist diggas, though unlike the diggas, wanting to be orks is the exact opposite of their desires.
Sadly, these guys have barely been featured in lore since the Armageddon Campaign way back in the day, they never got models either, instead GW just used heavily war-painted Catachans. They did however get their own rules in Chapter Approved and, eventually, a DLC for Warhammer 40,000: Armageddon, which can be bought on Steam.