Fido is a stone wyvern who is the guardian of the Chattering Key, which it wore around its neck. It appeared only in The Machine of Doom story novel.
Story
Fido was the stone wyvern that guarded the Chattering Key to keep those who are tempted by the Machine of Doom from stealing the very artifact that will unlock the tomb that held the weapon. When two trolls were about to steal the Key, the artifact itself let out an alarm, and Fido awakened, blasting the would-be thieves to smithereens. Although Spyro, Eruptor, Gill Grunt, and Boomer succeeded in stealing the Chattering Key, Fido chased them down through the Forest of Fear, despite Gill Grunt and Boomer's attempts to stop it. Just as it was about to come crashing down on the Skylanders, Fido was soon destroyed by a beam of light generated from a pillar of the re-emerged Pyramid of Just Rewards.