Green Day (グリーン・ディ, Gurīn Dei) Is an overwhelmingly deadly Stand as its mold has the potential to massacre whole cities, with enough combat ability to pummel others with its fists. The Stand’s primary attack is to produce a potent mold that rots and destroys the flesh of those it infects in an instant.

This mold growth is triggered when the potential victims lower in altitude, a condition that applies even to individual limbs, forcing them to either stay immobile or go upwards.