Originally this wasn't meant to be an Instructable, more so a last minute costume. So things aren't exactly documented the best. That being said, this 'ible is very simple as long as you know what you are doing. I made it in two school nights, so you guys shouldn't have much of a problem with this. And you can use the same method for other designs as well.
Just a few rolls of duct tape, some cardboard, graph paper, rulers, a writing utensil and a computer with printer access are all you need to get going. Start by sizing up your image on the computer to fill up most of the page. This will give you more to work with. Then, if possible, lighten up the picture (the opacity). This lets you see the graph paper lines through the image. It didn't work so well on my mac (I'm sure there was a way to do it) so I had to extend the lines back over the image after I printed. Then, PRINT.
Next figure out how much to scale up the image. You can do so using a ruler and calculator. But you probably already knew that. Scale it so that the eyes will line up over your eyes and that the mask is not so bulky.
Now there is many other ways to do this, but I decided to just scale the sizes of the squares on the graph. The squares on the paper were 1/4 inch, so I made a 5/8 inch grid on the cardboard using a carpenters square. This has to be accurate.
Mark the lines for both papers with numbers, corresponding the ones on the paper to the cardboard. Then proceed to draw your image.
Using a knife (or scissors), cut out the image. You can also cut the eyeholes at this time. Now for the duct taping.
Make a border using the black, wrapping it around the edge. Then fill in with your other colors. It may help to trace the inner parts onto some plastic (a zip-loc works) and then transferring them to the duct tape. Now it's just a matter of placing the pieces and fine tuning how they fit. Like a jigsaw puzzle. To secure it to your head, take a cheap (preferably color coordinated) baseball cap and secure it with duct tape. Make sure that the hat is set to fit tight on your head before you tape. This mask is heavier on the right (your left), so you want it all to be very tight so that it does not tilt.
And there you go. A cheap, simple to make Angry Birds mask. Just wear a matching colored shirt and some comfortable pants and you're all set. Thanks for reading, remember to vote, and...