Boola Boola Knot in 8 Simple Steps

0. Have a piece of rope of about 2.5 m length ready.
1. Pull the bight (center of the rope) up behind two legs (or arms).
2. Take the bight and wrap the rope rope around the legs (e.g. two times).
3. Cross the bight over the standing end of the rope...
4. ... and go under the two wraps from the beginning (i.e. 2.).
5. Make an underhand loop into the stand end of the rope...
6. ... and push the bight through it.
7. Pull tight. Once the knot is fastened it creates a stable loop that won't tighten any further if you pull on the standing end.
8. If you pull on the loop/bight, the knot is relatively easy to untie by pulling the standing end back.