Zirconis, also known as The Jade Dragon, was one of the many Dragons that was killed by Acnologia. His soul resurrected in the Dragon Graveyard through the use of Wendy Marvell's Milky Way. Over 400 years ago, Zirconis was one of the Dragons who was opposed to the notion of Dragon-Human integration, as he believed that they were nothing but a food source. Later on, during the course of the war, Zirconis would become one of the many Dragons that were killed by Acnologia, the Dragon King. (Source: Fairy Tail Wikia)