This is not totally undisputed, but the replacement of ‘ulf’ (see English wolf) with ‘vargr’ (see Tolkien's Wargs) is a real development in Germanic languages, which would give this some credibility.This is fascinating
http://nowiknow.com/losing-the-htrkos-in-the-woods/
Our ancient ancestors were so worried about bears, they didn’t even want to name them because they feared [the bears] might overhear and come after them. So they came up with this word — this is up in Northern Europe — bruin, meaning “the brown one” as a euphemism, and then bruin segued into bear. We know the euphemism, but we don’t know what word it replaced, so bear is the oldest-known euphemism.
mwahahaha surprise surprise i turned this into a secret learning lesson and snerk is forced to deal with swedish spellings mwahahaha