An Etymological Dictionary of the German Language/Annotated/Rabe
Rabe, masculine, ‘raven,’ from the equivalent Middle High German rabe (rappe), Old High German rabo (*rappo), masculine, also Middle High German raben, Old High German raban, hraban, and Middle High German ram (mm), Old High German ram, hram (with mm for mn), masculine, ‘raven’; all these forms point to Gothic *hrabns. Compare Old Icelandic hrafn, Anglo-Saxon hrœfn, masculine, English raven, Dutch raaf, rave (compare Rappe). The proper names Wolf-ram, Old High German Hraban, and Modern High German Rapp preserve the old variants. Perhaps these cognates with Latin corvus, Greek κόραξ, ‘raven,’ Latin cornir, and Greek κορώνη, ‘crow,’ belong to the same root; yet the Teutonic form has a peculiar structure of its own, which, contrary to the usual assumption, presents some difficulties.