This is the “snare knot”, which I have to admit was new to me. It did look familiar, however! The animated knots website describes the similar poacher’s knot, aka strangle snare or a double overhand noose, as a double overhand on a bight. It also provides the useful information that this is a good knot for high modulus ropes that might fail with knots such as the bowline.
From the double overhand on a bight comes the triple overhand, scaffold knot or triple overhand noose, another strong, useful loop.
While on the subject of loops, twisting a wire loop into a double loop for better locking:
The previous blog featured toggles tied into the middle of ropes. Two methods of doing this, one for a clove hitch, the other for the related constrictor knot.