I hear you can't keep more than one ig together. Well, yes and no. If you have an iguana and are thinking about getting another iguana, you can, just so long as you are prepared to set up separate housing if need be. Big igs often get along just great with little ones, and females can be just as territorial as can males. In the wild, iguanas have a very dynamic social hierarchy.
Males stake out territories and there is always a dominant male in any group.
In a large population there may be several dominant males but they may keep some distance between themselves. Subordinate males will challenge dominant males, sometimes succeeding, sometimes not, retreating to the outskirts of the colony group to try again another day, another year. One of the biggest problems with getting a second iguana is that most people have enclosures that are too small for one iguana let alone more than one. The smaller the space you try to keep them in, the greater the risk of agonistic behavior and of one or both getting injured or sick. Agonistic behavior are those behaviors associated with dominance.