The gray dwarf hamster or grey hamster or migratory hamster (Cricetulus migratorius) is a species of rodent in the family Cricetidae.The gray dwarf hamster has gray fur and a head-body length ranging from 80 to 117 mm. It weighs 33 to 38 g. Its dental formula is 1.0.0.31.0.3.3. As it can deliver a painful bite, it is an idea to wear gloves when lifting this creature.