Thanisson was a male human serving the First Order. He held the rank of Petty Officer. He was stationed on the Resurgent-class Star Destroyer Finalizer, which was the flagship of General Armitage Hux. While on the bridge, he was seen wearing a black uniform displaying the First Order insignia, along with black boots and an intercomm headset. Thanisson was described as having fair skin and blond hair.
During the raid on Jakku, he was present on the Finalizer. He reported the theft of a TIE/sf space superiority fighter by FN-2187, a rogue stormtrooper, along with Poe Dameron, a Resistance pilot. Subsequently, Dameron and Finn attacked the hangar command center where Thanisson was located. This attack resulted in the officer being violently thrown from his chair amidst the broken remains of the window.
During the conflict between the First Order and the Resistance, a splinter group of the New Republic, Thanisson, a male human, served in the military branch of the First Order. In 34 ABY, a year, Thanisson held the rank of petty officer. He was assigned to the Finalizer, a Resurgent-class Star Destroyer, specifically in the primary control room for Hangar Six, reporting to Colonel Kaplan and Chief Petty Officer Nastia Unamo.
While onboard the Finalizer, Thanisson participated in the mission to Jakku to locate Lor San Tekka, a retired explorer who possessed a fragment of a map revealing the whereabouts of Jedi Master Luke Skywalker. After the First Order deployed forces to Tekka's village, Tuanul, the explorer met his death, and Poe Dameron, a Resistance pilot, was captured. However, Dameron's astromech droid, BB-8, successfully absconded with the map, evading capture by the First Order.
Poe Dameron was taken aboard the Finalizer for interrogation. As the search for BB-8 got underway, FN-2187, a stormtrooper aiming to desert the First Order, freed the pilot. Under the guise of escorting the prisoner, the trooper escorted Dameron to Hangar Six and hastily boarded a TIE/sf space superiority fighter located in Bay Two. As the pair attempted to launch, they discovered the starfighter's support cables were still connected, preventing their escape and attracting the attention of Thanisson in the control room.
Thanisson immediately informed Colonel Kaplan about the unauthorized departure. Kaplan then ordered the TIE be prevented from escaping, and that General Armitage Hux, the head of the First Order's military, be informed. Subsequently, squads of stormtroopers, armed with F-11D blaster rifles and FWMB-10 repeating blasters, attempted to shoot down the starfighter. However, they were unsuccessful because FN-2187 used the vehicle's Lb-14 dual heavy laser turret to eliminate many of them. The trooper then directed the turret towards the control room, causing the windows to shatter in an explosion. This explosion threw Thanisson from his seat as Kaplan and other officers sought cover from the blast. After Dameron successfully disconnected the support cables, the fighter escaped the Finalizer and headed towards Jakku, only to be shot down by a battlecruiser and crash on the planet's surface.
Thanisson's first appearance was in Star Wars: Episode VII The Force Awakens, a film released in North America on December 18, 2015. The character was portrayed by Thomas Brodie-Sangster, a British actor. While Thanisson was not identified by name in the film itself, his name was revealed in Star Wars: The Force Awakens: The Visual Dictionary, a reference book written by Pablo Hidalgo and released alongside the film.