An idea pinched from the Dwarf Fortress Discord (enclosed below) and most probably a couple of fantasy kobold cliches.
Sergeant Arch Dornan —
their gimmick is that they steal a lot, and they only speak in weird unga bunga language, so everyone hates them
honestly what I think they should do with kobolds is give them a dragon overlord
goblins have demon overlords, so why not give kobolds dragon overlords
also remove utterances
Its unfortunate that kobolds are such a weak race, and this suggestion helps boon them up with a half-borrowed mechanic from goblin towers, so that their sites aren't so pitiful and that they can work to build up their numbers in the shadows and remain a constant presence in the world, plotting, stealing and scheming so that one such day you can actually recieve a kobold siege as intended.
Great DragonsA Great Cave-Dragon or a Greater Dragon (titular) is a unique type of megabeast that generates with a kobold civilization as its ruler (using a token, instead of a default cave-site trait for modding friendlyness), it can't leave its position but will be a factor in the changing ages of the world.
Disclaimer: This cropped and doctored image is from the steam DF graphics, thankfully this example is probably too terrible and the wrong size dimensions to be useable or to be considered copyright but please do not redistribute. All rights to the steam release DF graphics pack lay with Tarn Adams, Zach Adams and the Kitfox team respectively It is a humanoid shaped cave dragon standing upright, with arms and legs, intact wings and the ability to speak and breath fire (with smoky breaths), aside from the natural features of a cave dragon such as albino scales and new horns to show off its age and power. It is entirely fireproof like other members of dragon kind, but moreso like aboveground dragons with full material immunity to its own fire.
All this besides, the position that greater dragons exist in is where kobolds revere them as false gods in a monster cult, and also weave plots to steal objects by tying in kobold theives and other believers in their religion or those that are bribable to steal artifacts. Once a quota of world artifacts and wealth has been taken, kobolds and their dragon masters will turn more aggressive against the rest of the world and start sending out armies to attack sites.
New OverlordsAs unique creatures, Great Dragons once they die cannot be replaced. However when a [FEATURE_BEAST] or a [MEGABEAST] with the [POWER] token and power of speech attacks the site, the kobolds will surrender to its will, and create a new monsterous master position to lead their plots and stealing.