It was created with Spike and rib stitches. Starting with the first spike on the bottom. Increase 2 spikes at two sides. The main part was knitted with spike pattern, finish it with ribs as neck collar.

knit
purl
yarn over
knit 2 together.
Slip 2 stitches to right needle, knit next stitch on left needle, pass two slipped stitches over the last knitted stitch (decrease 2sts.)