Possible inhabitants for a 18x12x12?

I have a 18x12x12 enclosure that is just being used as an occasional quarantine enclosure right now, but I’d like to find a more permanent inhabitant and I’d like to consider some reptiles before I look at invertebrates. It’s 18 long, and 12 tall/deep, and front opening. It has a lot of ventilation right now but I’m planning to make some acrylic panels to close off the ventilation if necessary. Are there any animals that this would be an appropriate size for?