there's a lot of inspiration that can be drawn from the eidacara biota:
https://en.wikipedia.org/wiki/Ediacara_biota'quilted' bodies seem to seuge well into Douglas Adam's intelligent mattresses.
The above ideas seem to borrow heavily from a starfish's radial symmetry.
what would a humanoid look like if it were 6 limbed? Maybe two legs, two heavy arms and two delicate arms for tool making? Maybe 4 legs and two arms (moving into centaur territory here)
What if we had a diamond body shape with a limb on each corner?
What if the elephant's trunk had led to tool use? A 4 limbed stocky plain's dweller that might build attachements for the heavy forelimbs for things like digging.
How about a fractal symmetry? Three limbs split into three fingers each, then gradually adpated into specialised tasks (so maybe a tough large walking 'toe/thumb' and then two fingers on each foot.)
How about hyperintelligent sloths (Alastair Reynolds I think)? Their houses would have no floor, but an impeccably designed ceiling. Surely a species born facing the stars is a good candidate for intelligence?
Moving to plains dwellers we're getting closer to pressures that might make humanoids. Hyenas become orks, kangaroos become well, kangaroos.
Avians? We have tool making birds already. How would Corvus Corax develop if left alone to exploit it's niche?
