The name "Tiber," referring to the river in Italy, likely has a pre-Latin, possibly Etruscan or Italic, origin, with a possible Celtic connection. The Celtic root "dubr" or "dubro," meaning "river" or "water," has been suggested as a possible source for the name, and this root also appears in the name Dover.
The name Rhine, used for the river in Europe, originates from Gaulish. In Gaulish, the river was known as "Rēnos," which was later adapted into Latin as "Rhenus" and Greek as "Rhēnos" during Roman-era geography.
Danube is an Old European river name derived from the Celtic 'Danu' or 'Don' (both Celtic gods), which itself derived from the Proto-Indo-European *deh2nu.
Those winged helmets that Romans depicted and the Horned helmets that are attributed to Vikings? Both are Celtic designs.
A Celtic helmet with a bird crest was found in Romania and dates back to the 3rd century BC. The crest featured wings that articulated, meaning they moved up and down when the wearer moved.