(demon Ronwe, from Collin de Plancy's Dictionnaire Infernal, 1863)
Ronwe is a lesser demon who provides knowledge in foreign languages. The staff he carries under his arm is perhaps for beating slow pupils -- he certainly has a very pedagogical look about him, and reminds me of several of my old teachers.
This demon may be the same as Ronove, mentioned in the Goetia and in Reginald Scot's Discoverie of Witchcraft, from which latter text I shall quote:
"Ronove a marquesse and an earle, he is resembled to a monster, he bringeth singular understanding in rhetorike, faithfull servants, knowledge of toongs, favour of freends and foes; and nineteene legions obeie him."
In past centuries the term "monster" was applied to a deformed human being such as the famous Elephant Man. In this sense Collin de Plancy's version of Ronwe is monstrous.