Mennis Duren, an alien with yellow skin, gray hair, and orange eyes, belonged to a sentient species. In 1 BBY, this individual was located at the Ring of Kafrene trading station. Cassian Jeron Andor, an operative for the Rebel Alliance, walked by Duren amidst the bustling streets of the station. At that time, the alien was standing near a Delphidian at a food vendor. Andor encountered the alien once more at the entrance of an alley, where the agent was scheduled to meet Tivik, his contact.
Later, Duren was seen in Jedha City, which is situated on the moon called Jedha. There, the alien engaged in conversation with a hooded figure close to some market stalls not long before the Galactic Empire brought about the destruction of the city. While on both the Ring of Kafrene and Jedha, Duren was wearing blue robes.
The character Mennis Duren was conceived for Rogue One: A Star Wars Story, the 2016 Anthology film. Dilu Miah played Duren, noting that the character's heavy cloak made the role challenging. The character's appearance was first revealed in the initial teaser trailer for the film, which debuted on April 7, 2016. Although the character was unnamed in the film's theatrical version, the "Rogue Connections" extra included in the home release identified him. This featurette also revealed the character's name was a tribute to Dennis Muren, a special effects artist at Industrial Light & Magic.