521. Kaleesh. Kaleesh are mask-wearing warlike primitives. (Gr.) They believe that those who achieve great deeds in life become gods after they die. They were wrapped up in a war with the Yam'rii, AKA the Huk, who are basically huge praying mantids. They didn't do too well. One of the heroes of that conflict, Qymaen jai Sheelal, would go on to become one of the most famous Kaleesh, under the name General Grievous.
There are some mild inconsistencies in Kaleesh size and leg structure owing to some of their more unusual members; most notably, Grievous's droid legs are probably responsible for the inconsistency, as most of the time Kaleesh are illustrated with relatively human feet.
Rating: 3/5. The Kaleesh are modestly interesting. Grievous himself is a bit more interesting (and horrifically tragic), because the Separatists for whom he worked were allied with his enemies from the war with the Yam'rii/Huk, and there's no indication he was aware of this. (Despite his tactical brilliance, I believe he was confirmed to have suffered severe brain damage at some point before he became Grievous, not surprising since there wasn't much left of him.)
522. Kalkals. The only known Kalkal wanted an interview with Jabba the Hutt, and one of the requirements was that he make Jabba laugh, but Jabba had heard the joke he came up with before. He had also heard a scream much like the one that the Kalkal made as he got dumped in the rancor pit before.
Rating: 2/5. We don't know much about the Kalkals, but I'm giving a point for a reasonable bit of dark comedy (even if it was a shaggy dog story).
523. Kallidahin, or Polis Massans. The Kallidahin became known as Polis Massans because a bunch of them were spending all of their time on Polis Massa, a space rock, digging for archeological information on a group who might be connected to their ancestors.
They basically have no faces and can't speak, and so use telepathy and sign language to communicate.
The place where Padmè gave birth to Luke and Leia was Polis Massa, and the droid that attended to her was one of theirs.
Rating: 3/5. A bit of mysterious weirdness (which these guys are) benefits any fictional universe.
524. Kalsunorans. The Kalsunorans of Kalsunor were apparently trounced by the Sith Empire, the old one that existed more than five thousand years before the movie era. (There are several more recent Sith Empires, and some other empires to boot.) The means by which they were trounced? Giant dark side-empowered crab monsters "dropped" onto their planet.
Rating: 3/5, by pure association.
525. Kalzerians. The Kalzerians have black teeth, black (it isn't explained what they mean by "black," though) leathery skin, and yellow eyes. And they're otherwise probably essentially indistinguishable from humans.
Rating: 2/5. Eh, reasonably interesting color scheme, but a little boring, and not much information otherwise.
526. Kamarians. I feel like I've told this story before: Han and Chewbacca were visiting this fairly primitive planet and showing them some holographic documentaries. They got a riot when they changed to an action movie, because the documentary was about water, and the primitive folks they showed it to lived in a desert... and so much water was a religious experience for them. (Ah, here we are, I offhandedly mentioned the incident here.) Anyway, not all of the Kamarians were nearly that primitive, and in fact others on the very same planet had developed nuclear weaponry and ballistic missile point defense independently of the rest of the galaxy. (Just why they bothered when they could have bought themselves some nice good stuff from an offworld contractor is beyond me, but hey.)
The Kamarians are also cool bipedal insectoids, so that's all good.
Rating: 4/5. The Kamarians are pretty unusual in terms of their unusually well-developed culture and technology level compared to the rest of the galaxy, and in the fact that they vary greatly from region to region on their own planet (with desert-dwelling primitives and rather advanced if feudalistic cities).
527. Kaminoans. The Kaminoans are those tall, excessively thin aliens that were described as very good cloners and who created the Clone Army for the Republic. They are, incidentally, totally into eugenics, as in they actually practiced the heck out of it. Their culling of the overly sentimental is probably why they all sound so calm all the time, and their culling of just about everybody is probably why they all look alike. Aside from the cloning, of course.
Rating: 4/5. I like the Kaminoans, because they have the look of these gentle, ultra-peaceful people, but when you start digging into their background you realize, "Oh, hey, these are really horrible people."
528. Kanduh. The Kanduh are ambiguously canon, and even if they weren't, they'd all be dead.
Rating: 1/5. Way to be irrelevant, guys.
529. Kanzer Exiles. Apparently, a group of sapient reptilians, who may or may not have been exiled from someplace called Kanzer (the only known aspect of their origin is that they came from the Unknown Regions). One of their leaders apparently made a temple the size of a planet at some point.
You go, may-or-may-not-be-exiles.
Rating: 2/5. I was leaning towards a 3, but all that ambiguity was a bit too much.
530. Kardurans. Kardurans apparently form dancing troupes.
Rating: 1/5. Yeah, like no other species ever would, right?