A fake knot (i.e., a knot equivalent to the unknot) created by tying a square knot, then looping one end twice through the knot such that when both ends are pulled, the knot vanishes.
Chefalo Knot
See also
Square KnotExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Chefalo Knot." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ChefaloKnot.html