The creeper's blocky geometric shape makes this a great beginner project for people unfamiliar with sewing. Also it's your best shot at giving a creeper a hug without it costing you the north wall of your house.
Step 1: That's a very nice EVERYTHING you have there...
Erasable Marker - you can find one made especially for fabric at any craft store
Fabric Shears - Aka big ol' pair of scissors
Green Fabric (fleece is good) - About half a yard should do, go to the fabric store if you don't feel like punching sheep and cooking cacti
Matching spool of thread
Fiberfill - Stuffing
Either black embroidery thread or black fabric scraps
Step 2: Anatomy Of A Creeper
Head: 4" X 4" X 4"
Body: 2" X 4" X 6"
Legs: 2" X 2" X 3" - Make four of these
Map out the panels for each side of these boxes on your fabric. Be sure to keep about a half inch allowance around the edges of each outline. Keep in mind that you do not need to cut out the top side of the body because it is closed off by the creeper's head.
When you cut the pieces out do not cut along the lines you drew. Instead, cut about a half-inch to a fourth-inch outside the line.
The pieces should be easy to recognize, but if you think you will have trouble mixing them up I suggest labeling each part, or cutting out only the pieces of the section you are working on.
Step 3: Pinning
First line up the sides of two pieces of a body part and pin them together where they will be attached. Be sure to pin them together with the lines you drew facing out.
Step 4: Stitching
For those of you unfamiliar with sewing, you do this by feeding the thread through the eye of the needle. After cutting off a length of thread, tie the two ends together with a large knot. This is done essentially by tying several knots in one spot.
To start stitching, push the needle through the two pieces of fabric at the corner you drew on. Make sure the needle comes out at the same corner on the other side. From that side, push the needle back through the fabric a little bit down the line. Again, make sure it comes out the other side on the line. Continue like this down the line, removing the pins as you go. This is a basic running stitch.
Make sure to double back on the first stitch of any new piece of thread to keep it anchored securely.
When you reach the end of your seam, double back once to create a loop. Feed the needle and thread through the loop and pull it tight to anchor. For added security, do this twice before cutting off the excess thread.
Step 5: Form the Legs
Flip it over and pin down the last remaining piece. This time only stitch around three sides, leaving the last seam open.
Step 6: Om nom nom
Take a handful of Fiberfill and stuff the the leg part until it's nice and plush. Pay attention to stuff the corners so they puff out into the desired blocky shape.
Fold in the edges of the open seam.
Step 7: The Slip Stitch
Start your thread from the inside the fold of one side. Go across to the other side and prick the needle in and back out again, catching a little fabric along the edge of the fold. Go back across and do the same on the other edge, lining up where the needle goes in with where it came out on the last fold.
Continue down to the end and tie off the thread.
Step 8: The Face
For my creeper I decided to embroider on the face. This part could be difficult for beginners who might prefer just to stitch on some black patches in the shape of the eyes and mouth. A third, even simpler option would be to use fabric glue, which you could probably purchase wherever you found your fabric.
Patching the face
I'm afraid I don't have pictures but hopefully this will explain it.
Start by drawing out the outline of the face on the black fabric (it could be difficult to see on black, be sure you will be able to spot your line while you work). Cut around the shapes of the eyes and mouth leaving about a half-inch to a fourth-inch space between the cut edge and the line you drew. Fold in the edges along the lines. If your marker will clean off easily or is camouflaged by the black fabric, fold with the lines on the outside. If the lines will show, fold with them inside.
With the edges folded in, this is what the patch will look like on the front of the head.
Arrange the patches on the face of your head cube and pin them down. Be sure to pin the folds in place while you are pinning the whole patch to the head. Now you should easily be able to perform a slip stitch between the folded edges (along the line if you can see it) and the green fabric directly below it. When you are done there should be no loose fabric edges sticking out and hopefully no visible stitching.
Embroidering the face
If you are feeling adventurous enough, get yourself some embroidery thread and a needle.
Start by mapping out the face on one side of the cube.
Embroidery works best when the fabric is stretched out as you work on it. Had I thought ahead I probably would have added the face before I even cut out the pieces. What I wound up doing instead was rig up a cardboard frame to hold the face taut from the inside.
To ready your needle, cut a length of embroidery thread. It usually comes as six or so threads bunched together. Separate one or two of these threads and use them to thread your needle. An embroidery needle is a special needle with a larger eye to accommodate the extra thread.
Starting from the inside of the head, feed the needle out at the top of the eye and back in at the bottom, trailing the thread down the outside. Poke the needle back out along the line right next to where the thread goes in at the bottom of the eye, sticking it back in at the top, next to where the thread comes out. Repeat working your way down the eye until the eye is properly filled in. Tie off the thread on the inside of the head. Make sure not to pull the thread too tight or your face will wind up scrunched up.
Do the same to fill in the other eye and mouth. This will take some patience and a steady hand.
When the head is ready, stuff it with fiberfill and close it up as you did with the legs.
Step 9: Stuffing The Body
Draw a 2" X 4" outline at the center of the bottom of the head. Use this box as the top panel of the body. Using the slip stitch, sew three sides of the body to the head along the line, leaving the back open.
Stuff the body with fiberfill through the opening and stitch it closed.
Step 10: Assemble The Parts On Your Crafting Table
Step 11: SSSSSSssssssssss...
Now run like hell.