Yipyak

Yipyak was the language spoken by kobolds. It was a variation of the Draconic language that sounded like the yapping of a dog.

Origins
Kobolds originally learned the Draconic language directly from true dragons. The earliest kobolds were instructed to speak Draconic in a variety of accents and dialects, and when they became independent of their dragon masters, they took their language with them, dispersing it among their various clans and tribes. As these independent kobolds interacted with one another, their inherited Draconic dialects mingled, creating Yipyak, the common kobold tongue. Kobold sorcerers also knew how to speak true Draconic, which required more exacting pronunciation than Yipyak.

Script
It was believed by elven scholars that Iokharic, the runic script of Draconic, was originally developed by kobolds, as dragons had little need to write. It originated with cave paintings used to record kobold history. Those paintings developed into pictograms, and eventually into the Iokharic script.