Building with Paper Mache

I feel like this blog has become pretty much about holidays, but I don't seem to be all that crafty lately except when I have to be.
This year, my boys decided they wanted a Plants vs. Zombies theme for Halloween. The older two wanted to be plants, and the youngest ended up as the de facto zombie (he likes zombies, it worked well). These are not the sort of costumes one finds at the store...
After much thought on how to build the plant heads (the majority of the costume), I settled on paper mache. I first tried crepe paper, thinking its weight and little bit of stretch would lend itself well to the round shape. I was wrong. It pretty much disintegrated. I moved on to small pieces of construction paper in the desired color. For the paper mache, I mixed about 3 parts glue, 1 part water, and painted both sides of the paper with it as I wrapped it around the balloon. Each head is made of a double layer of paper mache, followed by a round of modge podge to make it shiny and seal it.  I used a regular balloon for the pea shooter, and then created the snout using cardboard with paper mache over it. For the chomper, I used a punch-balloon, since it has a slightly more round shape. The chomper teeth are made from craft foam, and the horns are a triple layer of foam core that is attached with tacky glue. The leaves at the backs of the heads are made with felt.
I cut the neck holes a little snug, then reinforced them with the thicker (3/16") craft foam in a ring around the inside of the collar, and then wrapped them with felt that was glued and modge-podged in place. I figured this would make them sturdy enough to take on and off more than once, and also comfortable enough that they wouldn't bother sensitive necks.
I took some pictures along the journey, in case anyone wants to attempt to recreate these. They were pretty fun, and the kids loved them. They found themselves repeatedly photographed while out trick-or-treating.
The Pea Shooter:

 The Chomper:

 It was really hard to keep the chomper mouth from collapsing. The interior of this one is all sorts of purple duct tape and foam core, cardboard, basically whatever I found hanging around that I could use to support it.

 In the end, these turned out to be remarkably sturdy. They survived repeat use by a 6 and 8 year old. The chomper even survived a fellow kindergartener who decided to beat up on it (punching it several times) while it was on my son's head. These also survived a rain storm while trick-or-treating. So I have serious respect for paper mache and modge podge.
For the rest of the costumes, I painted a stem and leaves on black shirts, and had them wear black pants. Very easy.
As for the zombie, his costume was acquired at thrift stores and a couple pieces I had to purchase new (the tie and blazer). The cone I found at a party supply store. I drilled small holes in it and attached thin elastic.
And here is the finished product: