Thanks all. I might tweak it a little. As leonardo_davi guessed, my reference was the picture of a Displacer Beast in the 3rd Edition Dungeons and Dragons Monster Manual. I used the profile of a lioness to get the basic head shape.
My next challenge is texturing this thing! I've no idea where to start so any pointers to good tutorials (downloading Kurt's Cyclops tut now) would be appreciated.
As a useful tip ... the 3rd Edition Dungeons and Dragons Manuals are an excellent source of inspiration for monsters, weapons, armour - all things fantasy and middle ages. Not a bad game either