I have had many requests on how to make this costume. So, I'm going to attempt to walk you through the process. I'm sure you might be able to find easier ways to create it, but this is how I did this one. I hope this helps you! Sorry for not documenting this project with more photos. Should have enough for you to have a good understanding. If you have questions, please post them and I'll try my best to answer. Thanks!

This costume took me around 40-50 hours and roughly $100 to make.

What you will need:

-Cardboard
-2 Yellow & 4 White Poster boards
-Acrylic Paint (Blue, Light Blue, Black, Yellow, and White)
-Styrofoam
-Masking Tape
-Screen
-1 Blue Long Sleeve Shirt
-Lots of Gorilla Glue (2 - 18oz bottles)
-Paint Brushes
-Small Hand Saw
-Sand Paper
-1 Painters stick

Step 1: Design / Scale

The First step I took was to try and scale an actual Lego. Here are some pics showing a poor but effective way to scale the costume. As you can see, both pics don't match in height... but again this gives you a good enough idea of scale.

On the first pic, you can see two rows of numbers. The first row, is pixels in the photo. Each pixel equals 1.5 inches. In the second photo, each pixel equals 1.2

Step 2: Shaping Styrofoam

I ended up buying 12 - 1 1/2" x 24' x 60" sheets of styrofoam. I couldn't find thicker ones that were affordable. So, I ended up gluing these large sheets together with some Gorilla Glue (little goes a long way). Once these dried, I traced / mapped out the dimensions for the feet (The top of these feet came up to my knee (side note - I'm 5'11")). I then cut out the 2 circles for the top and bottom of the head as shown in photo. Also cut out 2 smaller circles. One for the top to reflect the Lego peg. And a slightly larger one for the bottom so I could cut a large enough hole to have it slip over my head without much friction.

Step 3: Building the Body

I then started on building the body of the Lego Man. For this I used some thick cardboard, masking tape, and more Gorilla Glue (Last thing I wanted was for this thing to break). I cut the cardboard at slight angles and then taped them together. After I was happy with the look of the body, I cut the white poster board and glued it to the card board. I covered the cardboard in poster board so the paint job would look better. I just used a small roller brush to paint the blue, and a small paint brush to make the black lines.

Step 4: Finishing the Head

This part was kinda tricky for me. Looking back, it doesn't seems so hard. I used some thin cardboard (cut to scale height). Glued it to the top and bottom yellow circles. Once this was done, I then added 2 yellow poster boards over the top of this thin cardboard. Any gaps that were left, I just filled in with more glue. Then used yellow paint to blend any areas that needed it. I then painted / outlined the mouth. Once I was happy with the look of it, I cut it out and attached screen to the inside of the head. This is where you can see through. I painted the screen white and then outlined the teeth. One pic below gives you an idea of the viewing area while wearing this thing.
The head is removable. This was very important due to how hot you get wearing this thing. The head stays attached to the body with 3 pieces of wood (a paint stir stick cut into 3 pieces). I just cut 3 holes into the styrofoam neck, filled them with glue, and stuck the sticks in there until they dried. I also cut 3 holes into the top of the body for the sticks to rest in. This makes the head not turn, and gives enough support to stay on when walking / dancing. See photo 4 for a visual.

Step 5: The Hands and Feet

The Hands - Same process as making the top and bottom of the head. I just stacked these styrofoam sheets until they were the correct thickness, glued them together, cut them with a small hand saw and then used sandpaper to get the correct look and feel. Once this was done, I painted them. I then took some cardboard, rolled it and made the rolls large enough for my hands to fit through. Glued the cardboard rolls into the hands and then painted them.

The Feet - I cut out of styrofoam, 4 L shapes (2 per foot, 1 for each side). I then just glued smaller pieces of styrofoam to shape each foot. Once the glue dried, I covered them with cardboard and poster board. Then applied some black paint. The one issue I came across was trying to figure out a way for my feet to go in and out of these with ease. I also need these fake feet to move as I walk. So what I did was, I put my foot in the fake foot and figured out where the top of my foot was and glued some more styrofoam to surround my foot. I really feel there may be a better way to do this.

Upper Leg - As you can see, there is a small bump that represent the upper part of the Lego mans legs. I used some styrofoam, covered with poster board for the right, left and back. And used cardboard covered with poster board for the curved front. I then glued this to the body. Sorry I don't have a good pic of this part. The last photo circles what I'm talking about.

Step 6: Details

I feel that it is important to take time and add details. The white spots on the eyes, to the Lego sign on his back. The small things go a long way.

Step 7: Final Product

I hope this tutorial has helped. I had a good time making it and an even better time wearing it out. Everyone loved this thing. Hopefully I described in enough detail to make it easy for all of you to make one. Good luck and let me know if you have any questions. Thanks for looking!