so, random thing of my setting for the night: where'd this setting's version of kobolds originate?
well, back in the distant past, the dragons had quite powerful magitech that allowed for full-on manipulation of any biological form on both the genotypic and phenotypic levels.
and the dragons themselves were rather large. they could maintain their devices through spells, but wouldn't it be so much easier if someone could just climb up in those machines to take a look and do the work?
so the dragons found a planet with primitive lizard-like people - in what was roughly analogous to a late stone age - and... reshaped them for their own purposes. these were the kobolds' early ancestors.
in modern times, many kobolds can be found in tribal societies tending to the needs of their dragon masters whose minds have been reduced, the dragons generally being neutral towards them. these kobold societies typically revere the dragon they serve as if they were a god.
outside of that, kobolds are frequently incorporated - by their own choice - into paradisian civilization, and thus are frequently found in and amongst other sentient species