He had been a prisoner of the Gnolls in Ashbarrow. The party watched as Gonu Feralmonger had a long one sided chat with him.
The party named him Yoda, and his language yodeling. After a while Düne was able to learn his language and have conversations with him.
He was a general in an army that fought with the gnolls against the mind flayers. That is, until the gnolls betrayed him.