Start with a package of 6 pairs of work socks. I used 4 pairs for a toddler sized 18-24 months. You may need more or less depending on the size of your kiddo.
Step 2: Find a comfy sleeper.
I started with a sleeper that fits him well. This will prevent the scratchy socks from irritating his skin. Also, I can take the costume off the sleeper after Halloween and use it again. It was important that I use something with a snap crotch, so I could do a diaper change with no hassle.
Step 3: Find some inspiration!
I started with a printout as well as a mini sock monkey, so I knew what I was kind of aiming for.
Step 4: Do a rough layout.
Lay the socks out roughly where you want them. I wanted to use the red stripe on the cuffs, as it would be four less hems to sew. The width of the socks were just right for his arms and legs, no need to add or take fabric away.
Step 5: Start cutting!
Cut off the sock toes and the inside seam of the legs. Don't throw anything away! You'll use it to stuff the tail later.
Step 6: Fill in the holes.
Fill the gaps in with pieces of sock. I tried to keep the body to mostly the ribbed part of the sock. I thought it would be forgiving when it came to hiding the seams. It was! The ribbed part is also stretchier than the rest of the sock.
Step 7: Cut armholes.
Slice from the top down on the shoulder where the sleeve will join on. This is the armhole, and in the next few steps, you'll sew on the sleeve...
Step 8: Sew shoulder seam.
Turn body part inside out and sew the shoulder seam. Both sides.