Wikipedia
Meriones unguiculatus, the Mongolian jird or Mongolian gerbil is a rodent belonging to subfamily Gerbillinae. It is the most widely known species of the gerbil subfamily, and is the usual gerbil species to be kept as a pet or experimental animal, when it is known as the domesticated gerbil. Like the Syrian or golden hamster, it was first brought to the United States in 1954 by Dr. Victor Schwentker for use in research. Forty-four pairs were caught in Mongolia and brought to England. They were described as "squirrel colors... with long furry tails." They are somewhat larger than mice, with a body about 12 cm long (and a tail of similar length), with body mass averaging 50-55 grams in females and 60 grams in males.
The Mongolian gerbil is classed as a "prohibited new organism" under New Zealand's Hazardous Substances and New Organisms Act 1996, preventing it from being imported into the country.