https://ja.wikipedia.org/wiki/%E3%82%B3%E3%83%9C%E3%83%AB%E3%83%88 seems to have a bit of a different approach stating that D&D 3rd ed. changed them to be more reptilian. https://en.wikipedia.org/wiki/Kobold actually seems to corroborate this. I played D&D since the end of the 1st ed. days and I think of them as kinda dog-like heads that were also scaly. I have a 2nd ed. Monstrous Manual, but it's on the other side of the world at the moment so I can't check.