I used a pop-up laundry basket for the torso of the costume and covered it with a large turtle neck shirt. I stapled the basket to the shirt around the collar and bottom hem, and then stuffed the sleeves with small dryer vent hoses. Then I covered the whole torso with paper mache strips of parcel wrapping paper. When it dried completely I dry brushed several layers of brown paint colors to look like wood, and then stapled and wired vines, leaves and small doll figures on the “tree trunk,” I used pyjama pants for the bottom half, stuffed the legs with large dryer vent hoses, and then paper mached the pants.
I used the same paint colors and dry brushed them to look like wood, but also glued wood mulch chips to the pant legs. I bought a metallic mask from the store, and dry brushed it to look like wood and glued grass on it to resemble hair. For the treetop, I used a bike helmet. I sanded it and then painted it to look like wood. I plugged the holes with styrofoam pieces and stuck silk tree leaves in the holes.
Related costumes:
Coolest Homemade Treehouse Costume 
Coolest Autumn Leaves Costume 
Original Homemade Shel Silverstein The Giving Tree Costume 
Homemade Artistic Tree Woman Costume 
Original Girl in a Tree Illusion Costume 
Coolest Fall Leaves Halloween Costume 
Cool Walking Tree Costume on Stilts 
Coolest Homemade Haunted Tree Costume