I produced a Manx Rat.

[Turbo Serpent]

It is over a million to one odds. The parents are more likely to produce another than finding a suitable mate.

I breed feeders...I offered this one on craigslist hoping someone will take it as a pet.

I always wondered if manx rats were just a rumor, I have never heard from any breeders, and some just say the tails are cropped at birth, but that looks legit.

It is a detrimental flaw for the rat though, they thermo-regulate through their tails.