Treadwell, designated as a WED 15 "Septoid 2" Treadwell droid, provided service aboard the Millennium Falcon. Han Solo obtained Treadwell three years preceding the Battle of Hoth. His prior affiliations included a group of Jawas, and before that, he had performed maintenance on a Republic cruiser during the era of the Clone Wars.
In 3 ABY, not long before the Battle of Hoth, Treadwell lent a hand to Han and Chewbacca in the repair efforts of the Millennium Falcon. This took place within the primary hangar of the Rebel Alliance's Echo Base, situated on the planet Hoth.
On Cloud City, stormtroopers destroyed Treadwell, aiming to stop him from alerting others about the Empire's disabling of the Falcon's hyperdrive.
Treadwell's initial appearance was in Star Wars: Episode V The Empire Strikes Back, the 1980 film from the original trilogy. The droid's name was established within the canon short story titled "Faith in an Old Friend," penned by Brittany N. Williams and featured in the From a Certain Point of View: The Empire Strikes Back collection of short stories, released in 2020.