The Okatu (pronounced oak-ought-ew) are, like the Klingons, an aggressive species that puts a very high value on their concepts of honor and a rigid code of behavior. Unlike the Klingons, they place more of an emphasis on the might of intellect than of muscle. Nevertheless, they are strong and vaguely bear-like, being closely related to a carnivorous dog-bear-like species on their world ("Okat", pronounced oak-ought) in much the same way that humans are related to monkeys. Their early history is filled with strife between packs and clans that seemed to come to an end shortly after their first recorded encounter with alien life - at that point, the Okatu became a single clan as their definitions of "us" and "them" rapidly changed.
20 or so years after they first acquired primitive warp technology from a Ferengi merchant in exchange for access to the planet's natural rich pergium deposits, a drone ship attack was launched on their world with the seeming intention of destroying all life on the planet. The Ferengi delegation that was there worked quickly, out of self-preservation, a desire to protect their investment, and (it must be said) some honest affection for the Okatu people, and managed to successfully defend the world from the missiles the drones were launching. Except one city, which resulted in the loss of over 6 million Okatu lives.
Okatu honor demanded revenge, and since the attack had apparently been intended to destroy their species, that was what they set about to do to their attackers. The Ferengi gathered intelligence for them - for a fee, of course - as to where the drones had come from: the nearby world of Sashune. The Okatu put together a bioweapon to eradicate life from Sashune, and launched it. It was devastatingly effective, and the native Nesho people (unbenownst to the Okatu, a gentle, peaceloving people that had evolved from one of their world's herbivore species) were no more.
Later, the Okatu found out that the drones had actually been sent by a particularly nasty Orion trading consortium who were attempting to free up the pergium deposits that the Okatu were trading to the Ferengi, and when questions began being asked about the drones, the Orions had seeded information that another world that was refusing to pay them protection had been responsible - Sashune.
The Okatu were furious, and undertook to wipe out these Orions. But also, their code of behavior, going back to even before their recorded history, required that if an Okatu killed another by accident, that he then had to take that Okatu's place in all of his responsibilities: work, personal, all.
So after years of intensive research on the planet Sashune, a meeting of the clan elders was held that included input from almost every component of Okatu society, and extensive input from their behavioral and medical sciences. It was decided that a portion of the Okatu people would go and live as the Nesho, upholding their traditions and cultures and even using artificial aids to attempt to BE them, to as great an extent as possible. In an effort to appease their client's anger over the poor quality of intelligence product that had been acquired for them, the Ferengi offered their assistance in this effort, as well.
The Okatu continue to have strong ties with the Ferengi, whom they realize were duped and were also targets as much as they were. The "Nesho", OTOH, eventually joined the Federation, as that is what the Okatu that have taken up their role have determined that they would have done.
Lt. Babalen is a Nesho, and an expert xeno-biologist and xeno-linguistics specialist aboard the U.S.S. 24th-or-25th-century-Hero-Ship. He comes from an aristocratic family back on Sashune that has managed a district of one of the southern continents for almost a thousand years. Except, of course, that that isn't true. He's an Okatu, and that is the role that the Okatu's "Nesho Reciprocity and Preservation Council" has given him to play, since birth - to the extent that he has no Okatu name.