Unlike any other species of turtles, Gamera has the habit of walking bipedally rather than on all fours, though he will occasionally walk quadrupedally in his first three films. Gamera is capable of using his upper limbs in the same manner as Godzilla, as his forelegs have appendages much closer in construction to hands than feet, and is capable of grappling with opponents and manipulating objects. His mouth is filled with teeth, unlike any living modern turtle (several types of extinct prehistoric turtles were toothed, however), with a pair of large tusks protruding upward from his lower jaw. Gamera is also usually seen with very large human-like eyes, adding intelligence to his overall appearance. In the Heisei trilogy, Gamera has retractable bone spikes in each of his elbows.
Gamera is portrayed as an aggressive and destructive creature that deliberately lays waste to Japan after being awakened. However, he is shown to not be truly malevolent, as he actively saves a young boy at one point. After defeating the much more dangerous monster Barugon, Gamera is gradually seen as a heroic defender of Japan against other monsters. Gamera begins to actively rescue children from other monsters and alien invaders, while fending off attacks on Japanese soil by enemy monsters. Gamera also no longer attacks human settlements, except when temporarily mind-controlled by the Virasians.
- Gamera makes his first appearance in The Riders and the Guardian of the Universe.
- In a running gag, most people mistaken Gamera as Godzilla who had evolved into a giant flying turtle.