(From a picture)

Skull
With white
Chain 10
Row 1: DC in 3rd sh from hook and in remaining 7 stitches across. Chain 3, turn.
Row 2: Dc in first st, (ch 1, skip 1, dc in next st)3 times; dc in top of turning ch of previous row. Chain 3, turn.
Row 3: Dc in each st across, 2 dc in last st. Chain 3 turn.
Row 4: Dc in next 5 stitches, (ch 1, skip 1), dc in next 4 dc, 2 dc in last stitch. Chain 5 turn.
Row 5:Skip 1, tr in next 2 sts, ch 2 skip 2, tr in next 3 sts, ch 2, sk 2, tr in next 2 sts, ch 1, skip 1, tr in last st. Ch 3, turn.
Row 6: Skip first st, dc in each st across. Ch 3, turn.
Row 7: Repeat row 6
Row 8: Dc decrease over next two sts, work dc in each st across to last 2 sts, dc decrease over last two sts. Finish off.

For Granny Square:

Attach black to bottom right corner of skull, ch3.
Work two shells separated by ch3 in bottom right corner of skull (corner shell), ch 2, work shell in edge of row three, ch 2, shell in edge of row 5, ch 2 shell in top right corner of skull, ch 3, shell in same space (corner shell), ch 2, shell in center top of skull, ch 2, corner shell in left corner of skull, ch 2, shell in edge of row five, ch 2, shell in edge of row three, ch 2, corner shell in bottom left corner of skull, ch 2, shell in center bottom of skull, ch 2, sl st in top of beg st of row. End off.

Attach white to corner, work as for regular granny square, making shells in each ch2 space, and making corner shells in each ch 3 space. End as for previous row.

Attach black to corner, work as for previous row. When complete, sc in each stitch around, with 5 sc in each corner space. End off.

Note: I would probably make at least ten of these squares for a long scarf and sew two sets of five together so that the skulls are right side up, then I would seam the strips together (two tops of skulls together) at the center back. That way both ends would present the skulls as ‘right side up’.