Mantis Warriors

Name
Battle Cry	For The Emperor! For Redemption! For the Mantis Warriors!
Number	Unknown
Founding	Unknown. Believed to be 8th.
Successors of	Marauders (White Scars lineage)
Successor Chapters	None
Chapter Master	Khoisan Neotera
Primarch	Possibly Jaghatai Khan
Homeworld	None (previously Ootheca)
Specialty	guerilla warfare, hit-and-run, misdirection aided by divination by their Librarians
Allegiance	Imperium
Colours	Emerald green

The Mantis Warriors (formerly known as the Mantis Legion) were one of the chapters guarding the Maelstrom warp storm in Ultima Segmentum. When the Astral Claws rebelled against the Imperium, which came to be known as the Badab War, the Mantis Warriors joined them cause they were allied for a long time and it seemed like a good opportunity for some ass-kicking. First they looted a Fire Hawks' ship, shattered the Marines Errant attack force, and only lost when 2 other loyalist chapters kicked their asses.

All but 300 Mantis Warriors survived the fighting. They have been granted Empy's pardon (since the now-Red Corsairs were corrupted by chaos, but no one knew about it) and sent on a 100 year penitent crusade during which they could not recruit new marines. Space Sharks, with a silent acknowledgement from Fire Hawks, take an entire generation of Mantis Warriors' homeworld denizens and force them to fight to the death, taking those that survive with them to replenish their losses.

Mantis Warriors are notable for being one of the few chapters who used camo patterns on their armor - during Tranquility campaign their armor had yellow and black tiger stripes pattern (the fuck, they were fighting on planets made of tigers, or what? Tiger stripes is a camo pattern popular in Europe, L2military).

But most importantly, they are White Scars successors, which implies a heavy use of bikes, have subtle eastern MONGOLIAN HENSHIN influences, have a specific mutation that grant them extraordinary focus and combat skills during battles, and name their companies after giant bugs that live on their homeworlds. This means that it is extremely likely that at least one of them is a grasshopper-themed biker ninja with extensive bionic enhancements. Yep, the Kamen Rider exists in 40k. And it is awesome.

In the "Warrior Brood" novel of C.S. Multilazor, the Mantis Warriors are now seen as outcasts, but aren't Chaos or Renegade marines. While they were already given the Emperor's Pardon, the Imperium, being paranoid fucks to everything that casts a shadow, still holds a strong sense of distrust among the Mantis Warriors due to their treason during the Badab War, so their only real home in the grimdarkness of space is their Battle Barge.

One other interesting trait of the Mantis Warriors is a geneseed mutation similar to but distinct from the Blood Angels' Black Rage. Through deep religious meditation and acts of penance the Mantis Warriors can enter a state of supreme focus known as Battle Haze that gives them bullet time-style ninja reflexes. Problem is the state is permanent and those who enter it spend the rest of their lives completely catatonic whenever they're not in combat. Those who have entered the Haze have their own special Death Company-inspired unit called... wait for it... The Praying Mantises. You can groan now.