 A captive green iguana's diet should consist of fresh leafy vegetables, such as mustard greens, collard greens, dandelion, arugula, or kale, and access to fresh water.Green iguanas will thrive only in temperatures of to and must have appropriate sources of UVB and UVA lighting, or else their bodies cannot produce vitamin D that promotes calcium absorption, which can result in a metabolic bone disease that can be fatal.In some locales (such as New York City and Hawaii), iguanas are considered exotic pets, and ownership is prohibited.