also called crazy stitch or crazy shell. I reverse engineered this from a rug that was crochet for my grandmother as a wedding gift in the late 1930's. This is done a bit different than other similar stitches I have seen which I believe is why all edges on this are nice and "brick" like and even all the way around.
The scarf pictured is rather old and well used. i used a washable wool blend yarn and it is very warm.
Using the recommended hook for the yarn you choose to use (or the hook of your preference), chain in multiples of 5 + 2
row 1: DC in 3rd chain from hook and in next chain, skip next 2 chains and slip stitch into 3rd chain. This is one "brick" of 3 DC and 1 ch3 space (the 1st ch3 counts as a DC) * ch3, DC in next 2 chains, skip next 2 chains and slip stitch into the 3rd chain.* Repeat * to * all the way across ending in a slip stitch to the 1st chain stitch you made in the starting chain.
row 2: Turn and slip stitch over last 2 DC of previous row and in 1st chain of the ch 3 space. *ch3, 3 dc in same ch3 space, slip stitch to the 1st chain of next ch 3 space.* Repeat * to * to end. ending with 3 DC into last chain 3 space.
repeat row 2 for all other rows till scarf is desired length.
If you want to do it in 2 colors: I recommend crocheting length wise. If you do it width wise you will have a lot of ends to try to weave in up both sides. That is how I did the scarf in this photo and you can see all the ends starting to poke out. Doing it length wise won't change the appearance very much from what you see here.
At the start of each row you can leave a long tail and when finished with each row fasten off and you can leave the ends to incorporate them into a fringe if you like.
for each row turn and join w/a DC to the last ch3 space of previous row, 3 dc in same ch3 space and continue as + to + of row 2