Interesting. The word frog is used to describe a number of things besides the amphibian. These things are generally wedge-shaped for a particular function. Examples are the frog on a woodworking plane, used to adjust the blade position, the railroad track frog, which allows a train to move to another track, the violin bow frog, used to adjust tension, and also the wedge-shaped feature on a horse's hoof. I'm guessing that this wedge-shaped cable hanger could also be called a frog. You just happened to find one that illustrates the dual meaning.