Dinosaur Variant: When the Diplodocus was re-released as part of the Smithsonian Institution line under the name Apatosaurus, its motorized walking action feature was removed, the battery compartment that was located on its belly was covered up and the foot pads that facilitated the walking feature were removed. The Smithsonian Institution version is considerably lighter than the standard version due to the removal of the motor.

Figure Variants: The eyes on the Aries and Questar figures that are included with the Japanese version of the Diplodocus are painted black instead of the standard light blue. There is also a second, more rare, variation of the Japanese Questar figure that has both painted black eyes and black hair instead of the standard blond hair and blue eyes.