Diamondflame, a powerful blue dragon, is Kitten's grandfather.
When Numair and Daine reach the portal to the Dragonlands he initially forbids them from entering. When Numair informs him that Daine is the guardian of Kitten, or Skysong, he does not believe them since they are merely mortals. Daine proves their bravery by stepping through the fire to pass through the portal and subsequently Diamondflame sends Grizzle and Scamp to bring them into the Dragonlands. After a Dragonmeet is called to decide what to do with Numair and Daine, Diamondflame defends them and his decision in allowing them to enter the Dragonlands.
He, along with Wingstar, Kitten's grandmother, flew Daine and Numair back to Tortall. Shocked to find Broad Foot, the god of duck moles, aiding the humans with the Immortals War, he and Wingstar speak with Broadfoot about his reasons for involving himself with mortal affairs. Realizing that the war is more important than they first believed, Diamondflame and Wingstar aid Tortall and their allies in the war.
Diamondflame only appears in The Realms of the Gods.