I know it's late but I thought I would post it anyway. I was Russell from the Pixar movie Up for Halloween. I picked it since my dig is pretty much a dead ringer for Dug.
My first step was googling Russell the character an then googling other peoples costumes. I saw that I needed some wilderness explorer patches, a badge sash, his hat and backpack.
I bought a bunch of 4/$1 felt from Hobby Lobby. This is what I made the patches out of. I just googled a picture if the wilderness explorer logo and recreated it with the felt. Then I sewed one onto a khaki hat, one onto a yellow button down shirt ($1.75 from the Salvation Army) and one onto a felt pendent/flag thing from Hobby Lobby (2/$3 - %50 off coupon = $1.50). I also created a different WE patch from felt and grosgrain ribbon that is sewed on lower on the shirt. I also bought a $1 solid orange bandana from Hobby Lobby. Then I threw on a backpack (with the flag pinned to it), brown khakis, and hiking boots. The hardest part if the costume would have been the badge sash but luckily my sister had a girl scout one that I borrowed and it worked perfectly.
You can't tell in the pictures and couldn't really tell in real life either (sad face), that I made Layla a solid brown collar out fo some broadcloth and felt to mimic Dug's collar, but Layla had to much hair for it to make a difference. Either was most of the kids we saw during trick or treating with the kids I babysit for knew who we were. And that made me happy!
Since it was cold and I didn't want to cover my costume, I wore thermals, wool socks, and a yellow long sleeve shirt under my clothes to keep warm.