You will need:
Yarn in different colors.
A Cross Stitch pattern
A crochet hook. (I used size H)
You can get cross stitch patterns of anything, and you can even make your own.
I took a picture of the robot from here, and put it into Gimp. I used the mosaic filter to make it into a pattern.
Step 1: Following the Pattern
You start the pattern on the bottom right hand corner. First row you go right to left, second row left to right, 3rd row right to left, etc. You should leave your tail on your piece until you are finished, that way you always know that that is the bottom right hand corner.
Note: I printed my pattern too small. When you print it make it big, so that you don't go crosseyed counting squares.