First you make a draw from the pieces of the monster..

then cutting those pieces

then stitch the piece of paper with the fabric, it doesn't matter which color you like.. but i chose the gray one

and cut it with an area of one centimeter from the paper

do with all those pieces and then you've got this

you also have to cut those eyes and mouth and tooth.

first you sew the eyes and tooth

like this

after sewing those eyes and mouth
you can sew it on one of the monster body

now you are sewing those ears and arms together
and then put the body inside out and the ears and arms on the place where they belongs.

they you use the sewing machine to sew them all together.. and voila..
here you are!