Ug, along with the other trappers, was attacked one night by a mysterious dragon rider and lost numerous dragons they previously captured. Their fort was destroyed by a large ice-spitting dragon afterwards.
The next day, the trappers shot down a Deadly Nadder and met Hiccup and Astrid. Like the others, he was fascinated by Hiccup's dragon blade. Immediately, the two were assumed to be working with the other rider from the night before, though the Viking couple were quite confused about the ordeal. After Eret explains they work for Drago and need to deliver a new batch of dragons by tomorrow, the trappers tried to capture Toothless, but ended up losing Stormfly, and the Vikings. Not long after, Hiccup and Astrid returned to their ship and "surrendered." Hiccup explain it was unwise to threaten the dragons and implied they could destroy the ship. Hiccup then handed No-Name his dragon blade, while explaining how it worked. When No-Name released the gas, Ug sparked it unfortunately, causing a small explosion. Not long after, the other Berk Dragon Riders showed up unexpectedly, taking over the ship. After listening to Stoick's encounter with Drago, the riders left and the trappers were on their way.
Later, Ug and the other trappers watch as Eret is kidnapped by the Dragon Riders. He is not seen again for the rest of the film.
After the reform of Eret, his former leader, Ug, along with No-Name, Teeny, and the rest of Eret's Crew, appears to have reformed as well. He, along with the other crew members, came across a Night Terror covered in pine tar from a wrecked Dragon Hunter ship on Scuttleclaw Island. Ug and the others sent an Terror Mail to Eret informing him of the situation, sending him and the player on a quest to rescue the dragon.
Later on, Eret claimed that his old crew, including Ug, "wouldn't believe their eyes" if they saw him taking care of the three Rumblehorn Hatchlings.
Ug has blonde hair, and a clean shaven face with a prominent chin with tattoos on it. He wears a green and brown hat with mock "dragon fins" up the front. He also wears a short sleeved, light brown tunic, with a dark brown fur shawl over it. Ug also wears light brown sued pants, and dark brown fur boots. On his hands he wears fingerless leather gloves.
He gets along well with Eret and his other team mates. Eret seems to trust him when Ug tries to get his attention because he immediately listens and looks to where Ug is looking.