(technically Rattus Norvegicus, although they've been bred in captivity so long Rattus Domesticus would be more appropriate)
Typically 18-22 cm long, with a tail approximately 18.5-24 cm in length, but selective breeding has produced some "dwarf" rats, as well as big, beautiful show rats. The ideal rat should be long and somewhat racey, but show strong bone structure, with a well arched loin. The tail (if not a tailless rat) should be thick at the base, and taper to a fine point, free of kinks, and as long, or slightly longer, then the body.
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