Taranullus was a famous lithographer from the planet Centauri VII.
His series Creation was found by Dr. McCoy while browsing Flint's private collection on the planet Holberg 917G. (TOS: "Requiem for Methuselah")
This character was only mentioned in dialogue.
Several other individuals whose art Flint possessed in his collection (Brahms, Leonardo) were later revealed to have been Flint himself, who had assumed these identities.