where did the green iguana originally come from
It is  native from southern Brazil and Paraguay as far north as Mexico.
Green iguana
 it is native from southern Brazil and Paraguay as far north as Mexico, and has been introduced from South America to Puerto Rico and is very common throughout the island, where it is colloquially known as "gallina de palo" ("bamboo chicken" or "chicken of the trees") and considered an invasive species; in the United States, feral populations also exist in South Florida (including the Florida Keys), Hawaii, the U.S. Virgin Islands and the Rio Grande Valley of Texas. Green iguanas have also successfully colonised the island of Anguilla, arriving on the island in 1995 after rafting across the Caribbean from Guadeloupe.
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Green iguana [SEP] Introduction
Virgin Islands and the Rio Grande Valley of Texas. Green iguanas have also successfully colonised the island of Anguilla, arriving on the island in 1995 after rafting across the Caribbean from Guadeloupe. A herbivore, it has adapted significantly with regard to locomotion and osmoregulation as a result of its diet. It grows to in length from head to tail, although a few specimens have grown more than with bodyweights upward of . Commonly found in captivity as a pet due to its calm disposition and bright colors, it can be very demanding to care for properly. Space requirements and the need for special lighting and heat can prove challenging to the hobbyist.