Komodo Dragon Costume

Hello all! I joined this forum because I realized I'm in over my head and you guys know everything!

I've made costumes before, but this is ridiculous (for my level of expertise, at least). I'm making a komodo costume for a mascot and this is how far I've gotten.

First, I made a komodo head model in blender.

Then I built in in pepakura.

Here's a better picture.
(sorry for hugeness)
That's all the progress so far. But, I have a few questions.

First, know that this is a very low buget costume. I'd like it to look smooth, look good, and take a bit of roughhousing if anyone tries to be funny. But I'd prefer if it wouldn't cost too much, as it's all coming out of my pocket and I don't have a steady income.

So first, hardening. I know the best way is epoxy resin, or so I've heard (never used it before). Are there any other options? Paper mache or something? Like I said, I want to to be sturdy, but I want to cut costs at every turn.

Second, smoothing. Again, I've heard Bondo, but I've also heard of less toxic and more cost effective ways such as spackle and plumbers putty.

And that's all the questions I have so far. Thanks for reading!

I'm actually probably fine with getting Epoxy resin: I've heard it's non toxic and hardens stuff well. Besides, it's not expensive when I think about how much I'm going to use it after this costume. It's just the Bondo stuff I'm majorly worried about. I've read it's very toxic, especially the dust from sanding it. I'd just rather not get into that mess.

So, any alternatives?

This already got buried under plenty of other projects. But I do need help guys!

As promised...

This is for a mascot costume so you may want to lay foam over the paper head, and skin it with a fabric.

Thanks! It's a little late now though, the competition was last Friday. I can see why you said that, though, the helmet did get a little banged up, which could have been prevented by the foam.