Out of respect to writers you have to read the book in the way in which the author visualised it going out into the world.
I have never had trouble with any actor being able to visualise things. They are amazing. As long as you have your monster head on a long stick so you can hold it up there and you can wave it around and let them see it and explain it to them they are just great.
I know that I've got big ears and a big forehead and that my hair sticks up. But I'm happy with myself. I'm not necessarily trying to win a beauty pageant here.