They're all Shokan....half-human dragons. There are just variations of the species.

I actually find it quite amazing that Kintaro is half human, half dragon and half tiger.... WOW did i missed something? Let's do our maths here, shall we?

One half of human;
One half of dragon
and yet another half of tiger, yeah Kintaro has three halfs!! He is one and a half!

Think before you say something stupid like that, you moron.
They're all shokan, but the species vary. That's it.

That was uncalled for; you could've said all of that without calling him a moron.
Anyway, the Shokan are a race of half-Human, half-Dragon creatures, and just like we are all part of the same species and have different skin pigments and physiques, Kintaro has a different physique from Goro and Sheeva. No other animals were "spliced" into their DNA or anything.