I have seen this DNA styled knot on many decorative lanyards and it is surprisingly very easy to make.
The video is from sherman614 on youtube. The video is clear with superb audio instructions. Very detailed step by step procedure will get you going in no time.
Just make sure to use a longer paracord for braiding the knot unlike what the author just used. You may also use a single color if you wish.
This works great as key chain which gives a good grip to your hands. And yeah, also as an offensive weapon as the author stated.
If you don’t have a paracord yet, you can visit the Paracord Supplies section and you can purchase your paracords from there.