I have a very specific space I want to fill and will be custom building a tank to fit. Dimensions will be 129"x10.5"x21.5".

I am doing this a bit backward but not knowing what I want to keep in this spot. Any suggestions on what type of reptile/amphibian I should start looking into for this spot would be greatly appreciated. My main concern is the tank depth being 10.5" being a major limiting factor.