Cut out two large black circles, two small black circles, and a tan rectangle to fit on one of the circles.
Sew the rectangle onto one black circle, and on the rectangle, sew on the smaller circles.
Pretty simple from here:)
Sew the two black pieces together using a blanket stitch, but leave a gap to stuff it and..
~IF YOU WANT A KEYCHAIN~
Sorry, but I might explain this in a weird way, but it's pretty easy. Okay, so..cut a little 1 inch piece of the ribbon, and fold in half. Sew the ribbon in the gap (I suggest switch to a running stitch, and then back to a blanket stitch if there is still room to sew.) that you left for stuffing.
Stick the keyring on the ribbon, and WAH-LA! You have a little ninja to take around with you:)
Pretty easy, huh?