Knots you need to kno. Simple and reliable. Stopper knot Nine

Nine is a locking knot. Designed to thicken the rope, as well as form a non-slip loop anywhere on the rope (often at the end).
If greater thickening is required, a knot called “Double Eight” is performed.
Simplicity, self-tightening.
Efficiency - 70%.
When tightened under load, it does not come loose easily. However, nine is better than eight precisely because it is easier to untie after a load