First things first, Homestuck belongs to Hussie. Not me. If your clay creation does not turn out like mine, do not fear. You can get better with more practice. Don't be too hard on your self.
I also mixed my own colours to get the brown and grey so yours might be a tad different. I hope you have fun making this!
Read Homestuck here: http://www.mspaintadventures.com/?s=6
Listen to Cascade while you work: http://m.youtube.com/watch?v=0Mldr4sSV4s
Step 1: Things to Help You Start Creating!
~Small or large blade/knife to cut the clay with
~A shaping tool like a tooth pick
~A black sharpie
Step 2: Mix
Mix a small bit of brown clay with the gray. Don't put too much!! Mix until evenly coloured.
Step 3: Roll
Roll some white clay into a sphere. This will be PM's head.
Step 4: Shape
For PM's body you will take your clay mix of brown and grey and make a simple but slightly feminine body shape.
Step 5: Flatten
Flatten out a small piece of the mixed clay and then wrap it around PM's head.
Step 6: Hat
Make a triangular hat and put it on our now nearly done figure.
Step 7: Attach
Attach the head to the body and while your at it, make white clay legs and arms and attach the as well.
Step 8: Add
Add some lines on PM's outfit like you would a mummy.
Bake her in the oven and then draw eyes on her with your sharpie. Display your wonderful creation wherever you please!