The side view on this page is pretty much the best angle you'll get for a good look at how the head works. There's a couple of open mouths from the front too, if thats of any use either.
http://www.oddworld.com/universe/wil...te_design.html
There's also a back view at the edge there that, um...looks loike its guts a spilling out where its a*s should be or something. Seriously, I'm not kidding. Why is it like that? Weird O.o Well, can't expect much less from oddworld really, can you?