Yllen was the partner of Magnus, the captain of the passenger liner Stardream, with whom they had a child named Amy. In 3639 BBY, the Stardream was on a voyage from the planet Ord Mantell, and Magnus—who had been gifted a stuffed orobird for Amy—told Amy to ask Yllen for a cage for the pet. However, a few days later, the Stardream was overtaken by an outbreak of the rakghoul plague, and Magnus's communications to his partner became increasingly incoherent as he succumbed to the infection.
Yllen was mentioned in a Codex entry from the Rakghoul Pandemic World Event, which was added to the 2011 BioWare video game Star Wars: The Old Republic, in Game Update 1.1 in 2012.
Yllen was mentioned in a Codex entry from the Rakghoul Pandemic World Event, which was added to the 2011 BioWare video game Star Wars: The Old Republic, in Game Update 1.1 in 2012.