What can a baby iguana be housed with?

Hi. I have a 12 inch baby iguana that I was housing with my larger iguanafor a while and he LOVED the bigger iguana. Now he's in his own tank and I have just finished building him a inclosure of his own. Only problem is I think he's lonely now. His enclosure is 4 foot long , 4 feet high and 2 feet deep. So it will house him or a while at least. I was wondering why could house him with. The oter iguana is a lot bigger ten him and it made me nervous but he loved being with her. Just to let you kbiw. The larger one is a girl. The smaller one I haven't checked. Any info would be great.