Comment on The way I work by Hyrotrioskjan

Yeah, if you're deriving from earthly vertebrates, four legs is really the max. From an engineering standpoint, it's perfectly possible to have more than four legs; it's just wildly unlikely to evolve from something that does.

If you want to get funkier, might as well go all out and make up an entire alien ecosystem and anatomical basis to go with it; that's a whole lot more fun. Take Anne McCaffrey's Pern - the firelizards (and the bio-engineered dragons... with telepathy... ok, not the most scientific series. Still.) have six legs - but so do all the other native lifeforms on the planet, with everything else descended from colonial imports.