It is not actually known if the man known as “Nikolaus von Bibra” was a member of the “von Bibra” family. On the plus side, he lived not too far from Bibra bei Meinigen and records were very thin in the 1200s. On the negative side, he could be a monk just from the same Bibra or from one Nikolaus is listed under theology and satire. He wrote under the pseudonym “Occultus Erfordernis” and his satirical work is called Carmen Satiricum. The book referenced on this page was written in the 1990s.
Der ‘ Occultus Erfordensis’ des Nicolaus von Bibra (Deutsch) Taschenbuch – by Christine Mundhenk (Februar 2001)
Page 20-23 of Vol. 1 of the Family History discusses the issue of his connection to the family.