As well as standard gauge Crocodiles, there are also narrow gauge versions. The best known are the Rhaetian Railway (RhB)'s metre gauge locomotives of class Ge 6/6 I, the Rhaetian Crocodile. Several of these still run on passenger trains on special occasions. They are also used on freight trains in busy periods. The Bernina Railway (later merged with the RhB) also built a single Crocodile type, the Ge 4/4, nicknamed the "Bernina Crocodile". This locomotive survives and is being restored to operating condition.