[Catfish]

^ by the form of the drawbar it would be neither, only one horse. Or three maybe, don't now if possible with this double towing bar.
Anyway designed for one pulling creature (could also be a horse, oxen or whatever). But as written before this one is being pulled by one extraordinary man.
Another hint: It is not a roman design or build, just being used during this time. As said before an invented carriage.