this?
http://www.gloobbi.com/wp-content/uploads/2010/01/troll-chair.jpg
or this ?
http://t3.gstatic.com/images?q=tbn;ANd9GcQq32WYgR9jkni3PZqTFYGmjc-0JvjjerP16jsNfsUTJRY1HgI36g
or...
Sketchup is not very adapted for personnage modeling except maybe in toon modeling
For more organic try the free Sculptris