Cave Iguion is an enemy in Final Fantasy X. It is found in the Via Purifico after Yuna's trial at Bevelle. With the limited party available, summoning an Aeon with high Accuracy like Shiva might be the best strategy against it. Its attacks will cause Silence or Petrification, but it is weak to Ice, another reason why summoning Shiva is a good idea.
Iguion comes from "iguana." Iguana is a genus of herbivorous lizards native to tropical areas of Mexico, Central America, several islands in Polynesia and the Caribbean. Two species are included: the green iguana widespread throughout its range and a popular pet, and the Lesser Antillean iguana native to the Lesser Antilles and endangered due to habitat destruction. The word "iguana" is derived from the original Taino name for the species, iwana.