Clancy Brown will be voicing the fire demon Surtur in Thor: Ragnarok. He joins the already star-studded cosmic adventure presumably working alongside Cate Blanchett as Hela. Since the Asgardian God of Thunder will be spending some time in Hel, he and Hulk will have another villain to go up against.
It's been known that Surtur would be that threat thanks to a recent Funko figure. A giant beast, he has the power to manipulate fire with naturally devastating consequences to those he uses it against. He's got strength proportionate to his height, and since he towers at 1000 feet he's more than a match for normal beings. That said, he does have a weakness for extreme cold; maybe Thor and Loki could try their luck with the Ice Giants?
Brown won't physically be portraying the gigantic villain; that performance was done by the director of the film, Taika Waititi, who has been very hands on when approaching the film - including playing Surtur in motion capture. Waititi spoke to Comic Book after Ragnarok's SDCC Hall H panel about acting roles in the film (he also plays Korg), in the process confirming Brown's vocal talents:
"I did a little of the mo-cap stuff for Surtur, body wise, but then we have Clancy Brown doing the voice of Surtur. I'm playing a character from Planet Hulk called Korg. He becomes Thor's mate. It started off as a very small role. It wasn't me, I didn't do it, but the role has gotten bigger now."
Brown is a prominent character actor, having key roles in the likes of Highlander and The Shawshank Redemption, although in recent years he's moved away from live-action into voice acting. Perhaps best known for playing Mr. Krabs on SpongeBob Squarepants, he's lent his voice to hundreds of cartoon characters. With that in mind, his appointment as the vocals of a fire demon is totally fitting. And, from his live-action work, we know he can do menace.
Surtur made his proper debut in the official trailer unveiled at SDCC, going up against a rampaging Hulk, promising an epic fight; while Surtur might be a 1000 foot tall demon with near god-like powers, he's never faced the Hulk before. It was only a brief glimpse so we didn't hear what Brown will sound like, something that might come in a later trailer.
Source: Comic Book