As you can see, the Jagged Knife have the wrong symbol (Should be that orange circle thingy). They also seem to have a hilariously wrong race picture...
Nope, this is their symbol. I'll upload a pic of the Jagged Knife in the Foreign Relations screen tomorrow, DA 1.8e. It's just like the Dark Yor symbol but brighter. They popped up in my current Huge, Painful, Rare-everything, Super Warrior custom race game with the 'Exploitrons', stealing a planet from me and 1 from the Yor.
I retook my planet, but the Yor didn't, so the JK managed to live for several years before I crashed into their solar system to exterminate the 5 minor races who lived there. This extermination campaign was sparked off by the Vegans suddenly popping up on a Class 0 planet and stealing all my technology - so I had to kill them before they traded away my precious Positronic Torpedo 2 and Psyonic Beam. The Carinoids, Dark Yor, Jessuins and Jagged Knife got destroyed in collateral damage.
The JK is a galactic criminal group who have overthrown the government on several planets in a massive military coup, amazingly unopposed. Obviously they won't have cultural influence, or ever get flipped by cultural influence, or be a part of the United Planets, or any such thing that major races do. But it would be nice if they got a Korath-type AI. As such, minor races never have a distinct in-game personality - despite their descriptions, they all have the same generic behavior - spam freighters, build swarms of starbases, research wildly, yet build lousy ships, and then get exterminated.