The largest hamster in the world is the Black-bellied Hamster (scientific name: Cricetus cricetus/European Hamster), with notable characteristics as follows:
Physical Attributes
Size Data
Body Length: Adults reach 20–34 cm (including the tail), similar in size to an adult guinea pig.
Weight: Approximately 400–900 g, 3–4 times heavier than a common Syrian hamster.
Appearance: Brown-gray back, black abdomen, 4–6 cm tail, and white patches on limbs.
Ecological Traits
Habitat
Wild populations inhabit grasslands and farmlands in Central Europe and Russia, excelling at digging burrows up to 2 meters deep.
Behavior: Nocturnal, highly aggressive, and untamable; fiercely defends its territory against intruders.
Conservation Status
Classified as endangered due to habitat loss, with protection programs implemented in France and other regions.
Average lifespan of 8 years—far exceeding pet hamsters’ 2–3 years—but private ownership is prohibited.
This species’ wild nature makes it unsuitable as a pet, with research primarily based on field observations.