Dinosaur Hat

A fitted hood for an average size toddler with button strap under the chin and separately knitted and applied standing ridge decoration.

Requirements:  About 160 yards of Aran weight Yarn in main colour, and no more than 20 yards of a contrast colour.

One 3/4" button.

Note: I used Reynolds Ole Ole (2 skeins of main colour, 1 of the contrast), because this cotton makes a kid-friendly non-itchy fabric that has good body to hold the standing saw tooth pattern, and the colours are so dino-saur-like. Other suitable yarns for smaller sizes include Cascade Sierra (at 5st/in on 4.5mm), and Mirasol Cotanani (at 5.5 st/in on 4 mm). Soft wools with some alpaca or merino could make a nice winter version.
Gauge: 4.5 spi on size 7 needles

Saw Tooth Stitch

cast on 2 stitches
Row 1: K1 yo K1
Rows 2, 4, 6, 8, 10, 12: Knit all stitches.
Row 3: K1 yo K2
Row 5: K1 yo K3
Row 7: K1 yo K4
Row 9: K1 yo K5
Row 11: K1 yo K6
Row 13: K1 yo K7
Row 14: cast off 7st. 2 st remain.

Collar and Hood

In main colour, work 9 repeats of Saw Tooth Stitch, cast off all stitches on last row 14.
Without breaking yarn, pickup along straight edge 99 stitches by generally working 3 stitches every 4 rows. You may need to squeeze a few extras in as you near the end and realize you may not be up to count.

Row 1: (seed stitch edging) K1 P1 K1 P1,  then K6 K2tog, (K9 K2tog)7 times, K6, (seed stitch edging) K1 P1 K1 P1.
Rows 2, 4, 6, 8, 10, 12: P1 K1 P1 K1, purl across, P1 K1 P1 K1.
Continue to work seed stitch edging (sdst) in first and last 4 stitches throughout.
Row 3: sdst4, K5 K2tog, (K8 K2tog)7 times, K6
Row 5: sdst4, K4 K2tog, (K7 K2tog)7 times, K6
Row 7: sdst4, K3 K2tog, (K6 K2tog)7 times, K6
Row 9: sdst4, K2 K2tog, (K5 K2tog)7 times, K6
Row 11: sdst4, K1 K2tog, (K4 K2tog)7 times, K6
After decreases, 50 stitches remain.

To shape neck increases:
Work 5 rows straight. (don't forget the seed stitch edging) On 6th row, work 19 stitches, place marker, 12 st, pm, work 19 stitches to end.
Row 7: work 20st , inc1, slip marker, k10, slip marker, inc 1, work 20 st.

Increase 2 stitches this way every 4 rows 3 times altogether, then every other row 5 times, then at 4th row one more time: 70 stitches.

Work 12 rows, keeping markers in place, ending with having finished with a wrong side row.
At next row, knit to last 2 stitches before marker, K2tog, slip marker, knit 12, slip marker, slip1 K1 psso.
Decrease 2 stitches in this way every other row 3 times altogether.
Then decrease similarly every row 5 times. (you'll figure out the purl version, right?)
Place seed stitches on a holder, bind off all stitches to first marker, knit across to second marker, and bind off all stitches to last 4 seed stitch, then put these 4 on a holder, leaving a couple of yards of yarn still attached. You'll be completing the border across the top of the hood with this later, and if you're clever, also have left enough to sew the last edges together with it.

Rejoin yarn to enter 12 stitches, and continue working for about 18 more rows, or until this piece is even in length to the bound off edge of the side hood panels.  Bind off.

Sew corresponding upper edges of side hood panels to sides of center panel. 
Now work seed stitch border using still-attached yarn for about 14 rows, or until the border is equal in length to the bound off edge of the center hood panel, and then graft these active stitches to the seed stitch border from the other side.  Sew the seed stitch border edge to the bound off edge of the center hood panel.

Dino-Ridges
In contrasting colour, make 7 repeats of the Saw Tooth Stitch, and bind off all stitches, leaving length of yarn attached for sewing.  I used a whip stitch to sew the straight edge of the contrasting piece to the center of the hood, but you can use whatever sewing method you think is best.   

Chin Strap
leaving about 8" of yarn for sewing, cast on 5 stitches, and work 13 rows.  To make buttonhole: K2 yo K2. Work stitches in pattern on next row. Bind off one stitch at the beginning of next 4 rows, and draw yarn through final stitch.  Sew cast on edge of chin strap about 1 1/2" from the bottom of the seed stitch border on your favorite side.   Sew on appropriate button, sew in ends, and then try to convince your child to wear it long enough for a picture to be taken.

I think that this pattern worked in other colours would serve as a good foundation for all manner of dress-up creatures: in yellow with applied mane and little ears for a lion, in something sparkly like Ironstone's Paris Nights (paired with another cotton strand for a little bulk maybe) for a knight's helmet: anything goes!

I hope your little person likes this as much as mine does.