Nick, I understand completely how you are feeling, that you want to help this poor iguana. Now you and Yoda have a very special relationship with which you are both happy and in harmony. Bringing another iguana in will certainly impact on that ideal situation that already exists, and may only do harm to you and Yoda. You owe it to your own precious Yoda not to do anything to upset him. He will not be happy with another iguana, no matter how far away you try to keep it from him, he will probably know, and his personality may suddenly change for the worse. He may get jealous.
If you think you can keep this other poor iguana, and there is no one else to rescue him, and you decide to do it then please keep him far, far away from Yoda for reasons of health as well. Again, I totally understand your wanting to save this guy. Just step carefully here, please.
