For a couple of years now, ten buses operated Lothian Buses on their
route 26 (Clerwood-Seton Sands), that serves Edinburgh Zoo, have
featured animal advertisements to promote the location. With the
recent arrivals from China in the shape of two Pandas, a further
promotional bus has been suitably decorated.
http://www.lothianbuses.com/
Several images attached of some of the other buses on the route.
Tony Wilson