Born by 3 BBY, the Human male Allen Neff hailed from the planet Ertegas. He had a sister named Atril and, at the age of six, left his homeworld and moved to the planet Bespin. Allen eventually followed his sister in joining the Bespin Wing Guard, the main security force of the planet's Cloud City.
In 3 ABY, the Galactic Empire occupied Bespin with the intent to capture the Rebel Alliance's light freighter Millennium Falcon. When the Millennium Falcon landed on Cloud City's Platform 327, Neff was among the Wing Guard troopers accompanying the city's Baron Administrator, Lando Calrissian and his chief administrative aide, Lobot, in greeting the freighter's occupants. Upon Lobot's command, Neff and the other Wing Guard left the Baron Administrator and his aide alone with the Falcons captain, Han Solo, and his passengers, none of whom knew that Calrissian was in truth leading them into a trap set by the Empire.
Allen Neff was light-skinned.
During his service in the Bespin Wing Guard, Neff wore the standard uniform of the organization.
Allen Neff was created for the 1980 original trilogy film, Star Wars: Episode V The Empire Strikes Back, released on May 21 of that year. Prior to the film's release, he first appeared simultaneously in Shep Steneman's The Empire Strikes Back Storybook and the film's novelization, written by Donald F. Glut. Both of the publications were released on April 12 of the same year. Neff's scene was filmed between April 5 and April 12, 1979 on stage 2 of Elstree Studios.
On March 11, 2014, Neff was first named by the article "Rogues Gallery: The Cloud City Wing Guards," published in the Star Wars Insider magazine's 148th issue. Kevin Beentjes, Sander de Lange, and Tim Veekhoven, who wrote the article, stated that nearly all of the Wing Guard members described were "good guys" who opposed the corruption that was prevalent under the leadership of Cloud City's previous Baron Administrator, Dominic Raynor—with the exception of the ones who had been previously established to have been corrupt.