Treadwell was a WED 15 "Septoid 2" Treadwell droid who served the Millennium Falcon. Treadwell was acquired by Han Solo three years before the Battle of Hoth. He had previously been with some Jawas, and before that he had worked repairs on a Republic cruiser during the Clone Wars.
Shortly before the Battle of Hoth, in 3 ABY, Treadwell assisted Han and Chewbacca in repairing the Millennium Falcon, while it was in the main hanger of the Rebel Alliance's Echo Base on the planet Hoth.
Treadwell was terminated by stormtroopers on Cloud City, in an attempt to prevent him from warning anyone that the Falcons hyperdrive had been disabled by the Empire.
Treadwell first appeared in the 1980 original trilogy film, Star Wars: Episode V The Empire Strikes Back. The droid was named in the canon short story "Faith in an Old Friend," written by Brittany N. Williams and published in the 2020 short story collection From a Certain Point of View: The Empire Strikes Back.