The Gorgodon is introduced in Nightfall. It is a hybrid of four different animals that Lady Gisela created to guard her Nightfall. It consists of Flareadons for the fire resistance, Gorgonops for their fangs, Argentavises for their wingspans and Eurypterids for their stinging tails. They ended up much more deadly than Lady Gisela had expected, as genetics can be complex. It resulted in them having venomous fangs, wings, talons, spikes on their tail, the ability to fly, breathe underwater, scale walls, and last but not least camouflage themselves. Unlike her original plan of making ten, which was the purpose of the Everblaze in Book 1: Keeper of the Lost Cities, which was necessary for incubating these creature eggs which needed the pure untamed flame, only three survived as they turned out vulnerable to fire. Brant and Fintan had managed to steer the fire away from two of them, and Ruy protected one with a forcefield, leaving seven dead. To get past them undetected you must cover yourself in ash from Everblaze, which is how Sophie, Marella, Tam, and Biana got past them in Lady Gisela's Nightfall.
- Fitz, when he heard that the four animals made up a "gorgodon", said that the name should be gorgentaveridon because all the animals should get a part in the name.