PLEASE HELP trying to make a mouth for my rig

i am making a minecraft rig and this is what i have so far



but i want it to look like the one in this image http://prntscr.com/5oaeg2 but when i use subdivision surface it doesn’t work right is there anything i can do with nurbs to make the mouth like the one in the image

add some ring loops and or beveled edges to control the subsurf. I do not think you want subsurf for this.
I think shape keys is the way to go for animating the mouth.