Crab Stitch (or Reversed Double Crochet) is used as a decorative texture or edging. It consists of working double crochet stitches in the ‘wrong’ direction (from left to right for right handed knitters).

Crab stitch
1 and 2. After a right side row, do not turn.

2 and 3. Always starting with the hook facing downward, insert the hook to face upwards at the same time.Wrap the yarn and draw through, to finish off the dc as normally.

4. Insert the hook ready for next stitch