Giant Space Hamsters are a Dungeons and Dragons (D&D) creature that first appeared in the Spelljammer series. They are cute, brown-bear-sized rodents with thick fur and have achieved popularity among D&D fans, due in part to the fact that they are based on such a humorous and ridiculous concept.
Giant Space Hamsters were first discovered among the Tinker Gnomes, a race of highly technological creatures who primarily inhabit the world of Krynn. Tinker Gnome civilizations are divided into guilds, who each research and develop a different technological field. It was the Animal Breeder's Guild who bred the Giant Space Hamster. Characteristically, the Tinker Gnomes did not stop there, and continued to breed many forms of hamster, including the sabre-toothed giant space hamster, the carnivorous flying giant space hamster ("a regrettable if understandable line of inquiry"), the fire-breathing phase doppelganger giant space hamster, and the miniature giant space hamster (a dwarf variant the exact same size as the ordinary rodent).
Since the first edition of Spelljammer, Tinker Gnomes have grown a strong connection with the Giant Space Hamsters - mostly, perhaps, because of demand from the D&D playing populace for more of the rodents. Hamsters are now domesticated, used as both pets and livestock, and are also used to power Gnome Sidewheelers, an inefficient form of space ship that is powered by a series of Gigantic Hamster Wheels.
In combat, a giant space hamster will attack with its claws, and also attempt to swallow its opponents whole. They are, however, inclined to run away if given a chance.
In the Baldur's Gate CRPG (computer role-playing game) the Non-Player Character (NPC) Minsc had a rather dubious pet miniature Giant Space Hamster, called Boo.