Spit Fyre's egg was discovered by Jenna Heap and given to Septimus Heap, then known as Young Army Expendable Boy 412. Thanks to a series of coincidences that resulted in just the needed combination for a dragon hatching, Spit Fyre hatched for Septimus and Imprinted on him. Together, the two had many adventures as Spit Fyre grew to become a full adult dragon and an important part of Castle life.
Spit Fyre's egg is discovered in the temple of the Dragon Boat in Magyk by Jenna and given to Septimus (Boy 412); the gift was thought to be a rock because Jenna suggested to make a pet rock spell for it.
Spit Fyre is hatched in Flyte in the Keeper's Cottage, the cottage of Zelda Zanuba Heap, in the Marram Marshes. He gets his name because when he is born, he sneezes and spits fire at Septimus. At the end of the book, Spitfyre takes his First Flyte with Septimus and Jenna, witnessed by Alther Mella, Marcia Overstrand, and O Beetle Beetle.
In Physik, Spit Fyre helps Jenna hide the Dragon Boat by breathing Fyre, and then to find Septimus by using Seek. He breaks the Glass that allows time travel into the past and finds Septimus when he returns to the present.
When Jenna worries that the Dragon Boat is on the brink of death, she and Septimus have Spit Fyre conjure magykal Fyre in order to melt the way to the Dragon Boat. Spit Fyre discovers a kinship with the Dragon Boat, as she is in fact, his mother. Later, Spit Fyre wishes to join the group as they travel via the Dragon Boat to the House of Foryx, but is instead left to guard Aunt Zelda's cottage against Marsh Brownies.
Spit Fyre travels to the Desert of the Singing Sands to protect the Egg of the Orm that has been stolen by the Darke sorcerer Oraton-Marr. During this time, he lays in wait for many months, convincing everyone in the area that he has become a stone dragon. When the egg hatches, he imprints the Orm after it detaches its tail when Marr grabs on to it while still holding the egg. Septimus is thrilled to have his dragon back, even if he must share him with a feisty young Orm.