I would say a Rhaebo species, not a Rhinella. Smooth-sided toad (Rhaebo guttatus) is kept in a couple of European zoos (don't know for the US), so that's a possibility.
Looking up photos, that looks a lot more like it! The one in the center was a bit more.. elegant?.. than some of the photos, but texture-wise, body type, size, etc seem to match.
