I don't have experience writing patterns, and this one is basically made by trial and error. Post will be picture heavy to show how I worked it all out. Enjoy!
Chain 6 and slip stitch into first chain to make a circle
Make hdc into the circle you made with 12 stitches and slip stitch to join
Chain 2, 2 hdc into stitch, join and tie off and set aside leaving a 8-10 inch tail. This is one eye socket. Make another but do not tie off . . .
. . . on the second eye socket, continue a new round with 1 hdc in first stitch and 2 hdc in next. Repeat until you are halfway around the socket . . .
It is now time to join the other socket, leaving the tail facing the attaching socket, loop into a stitch from the second . . .
and begin repeating the 1 hdc , 2 hdc combination that you were doing on the first.
When you are almost ready to meet the bottom of the first socket, chain 4 to leave a space open for the nose hole in the skull. Finish the hdc pattern to the starting space, join with slip stitch and chain 2.
Use the tail you left on the circle and a darning needle to sew the circled together in the middle,
. . . leaving the triangle open for the nose.
Time for one more row of hdc aroudn the entire eye sockets. This time, do 1 hdc in first stitch, 1 hdc in next stitch, and 2 hdc in the following. Continue the 1 hdc, 1 hdc, and 2hdc pattern completely around both circles stopping at the beginning of the flat bottom.
At the bottom edge, 1hdc in each stitch until the start of the round. Join with slip stitch and chain 3 and turn.
Teeth row is made by crocheting 1 dc in the next 3 stitches, *chain 1, skip 1 stitch, dc in next*, repeat * to * twice, finish row with 2 more dc, chain 3 and turn.
Repeat entire row one more time, chain 2 and turn.
1 hdc in each stitch following row. Chain 2 turn and repeat one more row.
Work dhc in each stitch around the skull. This skull seemed a bit fat around the eye sockets in comparison to the mouth area so I decided to switch to single crochet around that portion. Be sure to work extra stitches in the corners as needed so your work will lay flat.