This is the final form the starfish known as Patrick star (from the Bikini Bottom Horror comic) has, consisting of a kaiju-like starfish monster to the eyes of any spongebob character and normal humans (25 meters big).
He can send his digestive system (specifically his huge stomach) out of his body, not only easily dissolving and digesting from the outside everything in his path, but also torturing their minds with allucinations while this happens.