Pholus was a wise and peaceful centaur who lived in a cave near Mount Pelion, a common stomping ground for his race. His friend Heracles came to rest from his labors, after capturing the Erymanthian Boar. Pholus had in his possession a jar of wine, a gift to all the centaurs; Heracles asked for a drink, but Pholus hesitated, fearing to open the jar. Heracles brushed aside his objections, opened the jar, and poured the wine. Several centaurs in the area smelled the wine, became enraged, and charged the cave, wanting their share.
Heracles attacked them with his bow and arrows dipped in the poisonous blood of the Hydra, killing several before chasing the rest into the woods. Pholus, intrigued by how so small a thing as an arrow could kill a mighty centaur, picked one up to examine it, dropped it, and it pierced his foot, the poison killing him instantly. The name Pholus was given to one of the centaur bodies that orbit between Saturn and Uranus.
Astrologically Pholus represents the small cause yielding a large effect; “taking the lid off” a situation with explosive results; and a catalyst or reagent spurring change or transformation. Pholus also relates to mass deaths, by whatever cause, such as natural disaster or terrorist acts.