How big of a taur do you get out of a human?

The title sort of explains what I'm asking, but here is some context;

Bill shouldn't have taken that help wanted ad for the mad scientist up the street. Now his legs were gone, and replaces with the body of bears. Granted, the bear part was really small, but it was still going to make driving his car a pain in his new stubby tail.

"Taur" by my definition; a 6 limbed creature, with a humanoid upper body and a lower body of animalistic creature, joined together at the hips of the human part and the base of the neck for the animal part. In the case of a Centaur this is a horses body joined to a human torso.

The scenario; A normal human is transformed into a -taur like creature. How this happens is basically mad science and besides the point. One of the constraints however is you still cant create or destroy matter, so the mass of the creature you end up with is the same of the mass of the one you started with, and corollarily will weigh the same in the same gravity.

Some things to note;

• The upper body needs to stay humanoid, but does not need to stay as the original torso it just needs to stay humanoid in shape and function, so this means you can take mass from here and move it around.

• The taur like body doesn't use magic to or anything particularly special to function, the only magic is making the body in the first place; this means (I think?) that the average density of the body should be about the same.

• The mixing creature should be mammalian. I'm not prepared to try and handle the explanation of how an amphibian cardiovascular system mixes with a human one or how avian hollow bones would be compatible.

Assuming that you start with a ~200-250lb human and that the ending creature is made entirely of the mass of the source human, and the mixing creature was something along the lines of a canine or feline rather then the long limbs of an equine or cervine, what size of -taur do you end up with?

bits to help guide the answers: I'm just looking for how big the creature is post transformation. Ex; You can't make a full sized centaur out of the normal mass of a person, but could you make a 6 month old centaur out of that mass? If instead of a horse you used a tiger, then what standing height and overall size would you end up with? Things of this nature.

I don't feel like this is a subjective question; the average density of living bodies means you have a hard limit on how big or small you can make something if you have a set amount of mass to use, and if your using familiar forms like horses or tigers and humans, then there should be a solid conclusion to reach.

• So instead of the mad science being the joining of two masses to create a tauric creature, the mad science is rearranging one mass from a humanoid shape into a tauric shape? I guess I'm confused because it seems like you'll just have a creature with the same mass/weight, and the only thing that might change is density. What are you looking for in terms of "size"? Oct 11, 2018 at 16:28
• You won't be able to go any bigger than a Miniature horse, even a pony is heavier than 250 lbs. Oct 11, 2018 at 16:36
• I'm a bit confused by the question: one hand we're mixing humans with something else, on the other hand, we're only using the mass of the human? There's something that I don't get there. If you're mixing two creatures, then you add at least part of their respective masses together. Would you mind to clarify?
– Sava
Oct 11, 2018 at 22:42
• @Frostfyre the intent is more that the end creature just has the appearance of a familiar animal + human hybrid, and the direction of the questioning is to determine the some guidelines as to the standing height and length of a six limbed creature structured like a centaur if you build one to be a specific weight. If the question is unclear or ambiguous I'd be happy to edit it further to clarify, I'm just not that sure what parts are unclear. Oct 12, 2018 at 0:36
• God... imagine a monkey-taur... or a monkey monkey taur.... eventually you just get a human centipede Oct 12, 2018 at 1:03