But… Its not a simple overhand. It has a loop.
If the tails were pulled all the way through it would be a Flat Overhand Bend. ABOK 1410. Often used to join two ropes for rappelling in the climbing world.
An alternative that is used to achieve the same result are interlocking long tail bowlines.
I am still hoping to name this knot because it is obviously not the same as a simple flat overhand bend and very different than a water knot (296).