Kobolds

Kobolds are the result of experiments carried out by a small number of chromatic dragons, some generations after the Great Ten.
Envying the power of their creator, these dragons judged themselves grandiose enough to be able to replicate the same method, dedicating their life to polish a ritual that would allow the reproduction of their species in a severely reduced time scale.
However, their confidence was much higher than their capacity. Even though the blood of their god flowed in their veins, all that the dragons managed to produce was a weakened and smaller form of the Dragonborn, initially obsessed with their own creators. These were the Kobolds, used for manual labor and, at times, abandoned completely by their creators and leaders to move on and find new purpose in their own lives.

So, there's a key difference between kobolds and dragonborn. Dragonborn were created accidentally from the intertwining of spilled dragon blood and a mass of fallen humanoids.
Kobolds were ritually created by chromatic dragons in an attempt to replicate dragonborn.

Kobolds are as varied as lizards and dragons, taking on various appearances. From serpentine to gecko-like or even in the case you saw, kind of reminiscent of sharks.