Zim is a sandwing-icewing hybrid, hatched during the Sandwing War of Succession. He fought during the last five years of the war for Blaze and Glacier, which is how he got his scars. He has neither frostbreath nor fire, and the venomous sting that most sandwings have is just a tail barb, no venom. He lives in Possibility, and works with traumatized war veterans, providing them with therapy and a friend. His position as a hybrid gives him a unique perspective on the tribes and the lines that divide them, and when he learns about Jade Mountain Academy, he believes that the it will not succeed unless dragons let it. He deeply blames himself for his mother's death, as he was fighting alongside her and they got separated.