Are there hybrids with Green iguanas ? :
Rock Iguanas at risk with discovery of new hybrids on Little Cayman
Rock Iguanas at risk with discovery of new hybrids on Little Cayman
I've just been doing some reading on the green iguana problem in the Cayman Islands. They were introduced accidentally to the island (I haven't seen anything reliable, but some sources say since the 1980s, and via released/escaped pets) and now they are a huge ecological as well as financial problem on Grand Cayman, which is the island to which the blue iguana is endemic.
This article from earlier this year says a recent survey showed half a million green iguanas on the island - https://www.caymancompass.com/2016/06/20/cull-to-tackle-caymans-500000-green-iguanas/ - although articles from the previous year said between 100,000 and 150,000.
They have been seen in small numbers on Little Cayman (the subject of vogelcommando's link) but most get removed by volunteers of the rock iguana conservation programme there; I saw one recent article which said 30 of 36 seen had been removed. They are getting seen more frequently on Cayman Brac, also home to rock iguanas, and are thought to be coming across from Grand Cayman on cargo ships.