This is a teenage mutant ninja turtle style ski mask with no mouth hole.

Sizing: this version fit multiple adults and kids who tried it on.
Notes:
I tried to remember and reverse engineer this as best as possible. But it was created during a weekend of day drinking, so there may be assumptions of stitch counts made here that aren’t quite right, especially around the eyeholes and the decreases to round over then close off the top of the head. Nevertheless this should get you pretty close, including weird decisions made along the way while winging it.

Worsted weight yarn, turtle green, Michelangelo orange, and white. I used a nice soft acrylic.

Needle size US 6 circular ~30” (used magic loop to accommodate circumference of the mask in the round)

Long tail CO 64
Join in the round, PM for BOR
K33, P1, K29, P1, SM repeat for 23 rounds
Continue to K all, SM at each BOR, for 6 more rounds (or until knitted tube is long enough to cover from under the chin to just under the nose)

Change to turtle eye mask color (orange is Michelangelo). Knit 5 more rounds in stockinette, SM at each BOR.

Eyeholes section:
K44, place 10 stitches on waste yarn, K10, RM
K54, turn, S1, P53, turn, S1, K53 for 10 rows
CO 10 stitches, pick up and K1 to rejoin in the round, K10. This leaves an open space in the middle of the front of the eye mask. PM for BOR. K one round.

Turtle eye mask German short rows:
SM, turn, wyif slip 1 purlwise,
Lift to make double stitch, P30
turn, wyif slip 1 purlwise, Lift to make double stitch, K to previous DS, knit DS together as one, K3
turn, wyif slip 1 purlwise, Lift to make double stitch, P to previous DS, purl DS together as one, P3
turn, wyif slip 1 purlwise, Lift to make double stitch, K to BOR
K two full rounds, SM at BOR and knitting DS together as one.

Top of head:
Switch back to turtle green.
Knit 7 rounds, SM at BOR
Decreases (approximate—actually not sure what the exact decrease pattern was after round 8…)
Round 1: K2tog, K9 repeat to BOR
Rounds 2 and 3: SM, K all
Round 4: SM, K2tog, K8 repeat to BOR
Rounds 5,6,7: SM, K all
Round 8: SM, K2tog, K4 repeat to BOR
Round 9: SM, K all
Round 10: SM, K2, K2tog, K4 repeat to BOR
Continue with K2tog, K1 repeat to last 8 stitches, switching to magic loop or DPN when needed.
K2tog last 4 times, to 4 stitches remaining. Cut yarn to leave a tail, thread tail through last 4 loops and remove needles, pull to tighten and weave in ends to secure.
(note: modify this section as needed with more or fewer K in between K2tog and/or more or fewer non decrease rounds in between decrease rounds to get the curvature in the top of the head that you want.)

Finishing:

Bottom edge ribbing:
(note: I added this at the end because I forgot to incorporate it at the beginning. You can start with ribbing if you don’t want to end up in this situation)
Pick up and knit every stitch along the bottom edge all the way around. PM for BOR.
Then repeat K1, P1 for 1x1 rib for 5 rounds.
Bind off with Jeny’s Stretchy Bind-Off (or other stretchy bind off method you prefer)

Form eyeholes:
Create a strip in the middle of eyehole section by putting two stitches, #5 and #6 of the held stitches, back onto needle and repeating K2, turn, P2, turn, for a total of 7 rows, then pick up and purl into 2 stitches of the cast on edge of the top of the eyehole section.

Crochet sclera:
Use white yarn
Starting with rightmost held stitch, single crochet into bottom 4 held stitches, 4 stitches along left side of eyehole, 4 stitches across top of eyehole, 4 stitches down right side of eyehole. (16 total all around)
Go around again with single crochet in four bottom SCs, then just 2 SC per side the rest of the way around (12 total all around). Tie off and weave in ends. Repeat for other eyehole.

Mouth:
Chain embroider vertical loops across mouth area to desired width. (Or however else you want to embroider on the mouth!)

Eye mask tie
Use eye mask color yarn
CO 2 sts, K2, turn
CO one stitch at each end while continuing in stockinette, until width is 12 sts and length is about 2.5”
Decrease by K2tog or P2tog (as needed per row) at each end, while continuing in stockinette until width is 7 sts.
At center back of main head mask, pick up and knit in the tie piece to attach it to the back of the orange section.
Continue to extend the tie piece by CO 1 st at beginning and end of each row, continuing in stockinette until width of this 2nd tie end is 12 sts. Then decrease using K2tog or P2tog (as needed per row) at each end, while continuing in stockinette until width is 2 sts.
K2tog for final 2 stitches, cut yarn and thread through last loop to tighten end.