A dead one, which makes it a prop.
I know that seems pedantic, but on a call sheet that would be listed under props, while creatures would be under effects and cast depending on how the creature is realised.
The giant dead Kong at the end of the '76 movie would be a prop, for example, while Rambaldi's full size animatronic is an effect.
(Also keep in mind I've no idea if it actually is the largest prop, but I wouldn't be surprised.)