Warning: SPOILERS for Thor: Ragnarok are ahead!
Although Hela served as Thor: Ragnarok's main antagonist, she wasn't the only powerful Marvel villain to give the God of Thunder trouble in the movie. At the beginning of the story, Thor found himself imprisoned by Surtur, ruler of Muspelheim. After learning from Surtur about the impending Ragnarok and how Odin was still alive, Thor broke free. But before he could defeat the fire demon and escape, he had to deal with a horde of fiery minions standing in his way, and you can see how those grunts were originally supposed to look in the concept art below.
Ian Joyner, an artist who previously worked on Guardians of the Galaxy Vol. 2, also submitted designs for Thor: Ragnarok, including this scene of Surtur's minions surrounding Thor. While the smaller ones certainly look formidable on their own, I dig the two giants carrying the flaming spears. Maybe if they had shown up in the movie, Thor wouldn't have managed to hightail it out of there. Ok, maybe not considering that Thor took down all of those blazing goons' boss, but still, it would have been cool to see them in action.
Because he wasn't at peak power levels, Surtur was soon defeated by Thor at the beginning of Thor: Ragnarok, and the God of Thunder took the fire demon's crown back to Asgard to put in Odin's trophy room. This proved to be both a wise and disastrous decision, because during Thor: Ragnarok's climactic conflict, our esteemed hero, who had lost Mjolnir and one of his eyes at Hela's hands, realized that he wouldn't be able to defeat the Asgardian goddess of death. The only being who could accomplish such a task was Surtur, and Thor resurrected him by putting his crown into the Eternal Flame.
Now alive once more and at full strength, Surtur didn't need any underlings to aid him in causing mass destruction. He did that all on his own, and while it resulted in Hela being vanquished, it also meant that Ragnarok came to pass as foretold, and Asgard was destroyed, though fortunately its citizens were evacuated. Surtur died in the process, so if you were looking forward to seeing him and his minions wreak havoc in other areas of the Nine Realms, you're out of luck.
Thor: Ragnarok is wrapping up its theatrical run, but the movie will be available on home media early in 2018. Thor himself will join the other major MCU heroes in the battle against Thanos and the Black Order when Avengers: Infinity War hits theaters on May 4, 2018. Don't forget to also look through our Marvel movies guide to see what else the MCU has in development.