Mosasaurus

6721 Mosasaurus is a Dinosaurs Set released in 2001. The set included 26 pieces and cost $10.00.

Info
Mosasaurus (which means "lizard of the Meuse River") was a large genus of Mosasaur from prehistory, measuring 48 feet long.

Variations
The Mosasaurus can also be built into a:

Dimetrodon

Iguanodon

Postosuchus

(All possible builds can't be built at the same time)