"Gizoid" is an ancient Echidna term for the guardian of the Chaos Emeralds and champion of the echidnas. However, it can mean different things to others:
- The term "gizoid" was originally bestowed upon Knuckles the Echidna, the eternal guardian of the Chaos Emeralds. Knuckles was unaware of this until events in "Skeletons in the Closet" (although a previous version of him was).
- Both Knuckles and Porker Lewis believed the name referred to an advanced version of the Guardian Robots. Guided by a message left by a previous version of Knuckles, the heroes determined that the "Gizoid" was the Guardian Robot that had been sealed away.