Looking at that Rancor pic reminds me of how much an incredible piece of design that was, given what we've had ever scince. Im thinking of Mimic, the Host, arguably even the Predator and beforehand Gigers Alien model (as they were designed to fit a man in suit).
Yes it looked clunkey and crap when it moved but the model still stands up beyond any creature design too date(or did they just model it on someones mother-in-law at the time? In that case they need much more slobber).
Giving it the green eyes would be a freash improvment (aswell as smoother movement that is).
And if hes been eatin too much Gammon Guard, that could explain the green eyes. <= thats crap.