Ready to make your little guy a dino hat?  Here we go! (And if you have a girl and want a new hat, keep reading, this can be girl-ified!)
You will need to color coordinating fleece fabrics. 
1/2 a yard of the main color and 1/4 yard of the contrasting color.
First we will start by cutting out the ear band portion of the hat.  You will want to measure your little one’s head circumference and then add about 1 inch to that number. The height of the band should be 6″. 
So if your child’s head is 18″ you would want to cut a piece of fabric this size: 19″L x 6″H.
Set that piece aside.

Now, to cut out the main portion of the hat.  I used the old hat to trace around, but basically you want to cut out a dorsal fin shape.  The width where this fabric meets the ear band should be 1-1.5″ more than your earband piece.

Next, cut out 8-10, 4.5 inch sqaures.  Take two squares, right sides together (if there is a right/wrong side on your fleece), and sew them together.  Cut them across diaganolly and then flip right side out to create your triangle “spike”.  Do this until you have 4-5 spikes.

Next you will take your dorsal fin pieces, again right sides together.  Place your spikes along the top of the hat – making sure the tip of the triangle is tucked into the hat.  I chose not to pin (I actually place the spikes as I go), but feel free to do so.  Sew from the tip to the bottom of the top of the hat making sure to catch the spikes.

Now flip the hat over and line up your ear band piece, seams together and pin. 

Sew together (No, you’re not crazy, the colors are opposite in this image – that is because this is another hat I made!).

This is how your hat looks so far:

Flip the hat inside out, line up the bottom seams and sew together, starting from the tip of the hat working towards the ear band.

That’s it! Your done!

Oops!  The hat is a little big?  No biggie!  Flip it back inside out and sew down that last seam to the inside of the current seam.  See, I had to do it once!

Now your little girl is jealous and wants her own cool hat?  If she isn’t into dinos, them you can make her this:

(I know, not a great picture – but she REALLY didn’t want to get off her Pillow Pet!)
Do everything as above, except add spikes.  To add the flower, just cut two circles, one bigger than the other, add a button to the middle and sew onto the ear band piece!