Base from my book-

Being an orphanage for most of his life, David never really thought he would under stand what it means to be in a family. His adventure started with joining the military after one year of Magic school, yet during a series of events that transpire in the coarse of a year, he ended up being capture by enemy combatants, then rescue by the famous person known in the universe. For his protection from forces he doesn't understands, he was moved in with Kakiookami's knights to train to defend himself against these evils.

During his training, Kak decided that David could learn a little more responsibility, so he decided to bring home an Darjeet egg from the local aquarium. Darjeets are creatures that is recently made from mixing DNA from Water Dragons, and the near extinct Boogle seals as the fish staple they eat develop poisons which almost killed them over night. The water Guienessnss Dragon stomach acids are able to break down these poisons, so combing the two, the Darjeet was created.

Althouse reluctant at first, he accepted the task of taking care of it and name him Mishwi.

(The name means Dark chicken meat, and yes i use that as a joke in the book once in a while.)

The Darjeet later learns how to water bend from a dream, and can form two water tentacles from his back at his will using his own magical storage.