Kraken

Nobody quite knows if Kraken's more machine or more dragon. 'Nobody' includes Kraken himself; he doesn't appear to have the faintest idea how it happened to him, or where he came from, or for what purpose a large chunk of his body was replaced with metal. He also doesn't seem to have the faintest idea how to be a civilised dragon any more, as he acts more like a slightly feral guard dog, patrolling the edge of the clan and growling at anyone who approaches. More than one visitor has nearly gone straight back up in the air imediately upon landing and being faced by not just an angry Ridgie nose, but a metal angry Ridgie nose.
He does, however, suffer a little from his bark being worse than his bite, as he's fairly easy to deal with once you know how- either you yell frantically for Tiana, who appears to have become his keeper somehow, and she drags him off you, or you tell him firmly that you have business to conduct and he must let you through. This generally works fine, especially if you've been there before; it only doesn't if he decides he doesn't like you.
Mather help you if he decides he doesn't like you.