Thanks so much for your response! I have definitely done my research on all of the lizards you mentioned and I worked in the pet care department of pet smart throughout high school and personally took care of Mali's and loved them and was thinking of getting one for my class. Since I am a biology teacher and I am very very aware of the importance of keeping the lizards in proper habitats with proper nutrician and all that good stuff. I just don't have any personal experience with iguanas. I am not worried about providing a wonderful habitat. I have the funds and the space for it. I am concerned about unpredictable behavior and also understand the stress of students coming and going. I have a colleague that taught in Coasta Rica and the schools there are apparently swarming with free roaming iguanas that the students interact with but of course that is in their wide open natural habitat which is totally different than being kept in a cage in a classroom.