We did this Yeti costume a few months ago with my daughter Mar. Several people has been interested in the steps to do it, so I decided to write this post, indicating the material and the steps to follow.
It is simple to do, although we need about 3h to complete it.
We do not buy any material, everything is recycled.
The foam, which is perhaps the most difficult to get, is from a local company, they receive their raw material between sheets of white foam, which they then do not use for anything. If you can't found, it can be replaced with cloth or paper.