The Calvin and Hobbes Wiki
Stegosaurus Model

Stegosaurus statue outside of museum.

Sabertooth Tiger

Saber-toothed tiger statue.

Theropod Dinosaur

In the 8/9 through 8/12 1989 story arc, Calvin and his parents go visit the Natural History Museum. It is strongly implied that they had been to the museum before, and that they were denied admission for some time because Calvin bit people while pretending to be a dinosaur. Outside the museum is a model of a Stegosaurus as it looked in the Jurassic. The façade is not seen, and little of the interior is featured; it is known, however, that the museum contains a representation of a saber-toothed tiger in its environment, the skeletal representation of a medium-sized theropod dinosaur, and a gift shop.

The Natural History Museum was also mentioned in earlier strips; it was stated that Calvin's family had spent "all afternoon" at the museum in a Sunday strip, and Calvin considered sending his findings to the Natural History Museum after digging up what he thought was a fossil.