Titivillus, sometimes spelled Tutivillus, is a demon, said to work on behalf of Belphegor, Lucifer or Satan in the Middle Ages, to introduce errors into the work of a scribe. He has also been described as collecting idle chat that occurs during church service.
He has been called the "patron demon of scribes," as Titivillus provides an easy excuse for the errors that are bound to creep into manuscripts. The demon of typos. (Wikipedia)