What could be the possible function of the muscle arrangement of muscularis layer?

Question

an animal organ part of the frog skin

Answer 1

The "muscularis" is usually part of the walls of the guts of many animals; the skin is usually a combination of connective and epithelial tissue.

If we're talking about the muscle layers of the gut, it has two layers of smooth muscle, one arranged longitudinally and one arranged circularly.  Both layers are involved in peristalsis, which moves food through the gut.