Pro heroes are the world's #1 defense against villainy and crime in the world of My Hero Academia. These heroes have many diverse costumes, personalities and fighting styles to match their equally various Quirks. All Might is almost like a control group, a Superman/Captain America hybrid with super-strength, thanks to One For All. His radiant smile and selfless personality also reinforce his position as a classic hero. However, not all pros are like that.
Whether it's Best Jeanist, who leans right into his denim aesthetic, or the martial arts rabbit Mirko, heroes have plenty of creative freedom with how they present themselves. However, some pro heroes look downright villainous, and there is even an in-world poll that tallies up who people find the scariest.
Kugo Sakamata, AKA Gang Orca
According to Episode 57 of the My Hero Academia anime, Gang Orca ranks #3 among all heroes who resemble villains, meaning civilians can take a poll to vote on who looks the most villainous. It's not difficult to see why Gang Orca ranks pretty high on this list. After all, orcas are large predators and are known for vicious behavior. Like the actual animal, Gang Orca is aggressive in battle, and he can use his Orcinus Quirk to release sonic attacks that can weaken and destabilize his foes.
While Gang Orca's abilities work best in water, they are still effective in the air, too -- and Shoto Todoroki and Inasa Yoarashi had to team up to stand a chance against him. Gang Orca even has a platoon of menacing henchmen who back him up during missions to add to his criminal perception.
Ectoplasm
One of the teachers at the U.A. school is known only as Ectoplasm, and he can duplicate himself with his Clones Quirk (not to be confused with the villain Twice's Quirk). Ectoplasm can make dozens of copies of himself or one giant clone. His abilities were best showcased during a mock battle that tested Tsuyu's Frog Quirk and Fumikage's Dark Shadow Quirk to the max.
Ectoplasm has a menacing and rough voice and a mouth of bared teeth, like a skull, and his shadowy head and blank white eyes only add to his villainous aura. He also wears a tall, beige trench coat with an oversized collar that might remind viewers of bat wings. Regardless of his true, heroic allegiance, Ectoplasm's costume makes him a clear contender for this in-world poll.
Enji Todoroki, AKA Endeavor
Fire has long been used among heroes and villains alike in the world of anime. Still, whether fire appears heroic or villainous depends on how it's used and the wielder's personality. Enji Todoroki/Endeavor is known for his rough and aggressive attitude and stern expressions -- not necessarily traits people would associate with a top hero. That, combined with his fierce Hellflame Quirk, bulky body, and flaming facial hair, Endeavor does seem somewhat villainous by default.
Endeavor is also an unlikeable figure, especially when considering his past and the treatment of his family. While he aims to improve himself, it doesn't change the fact that his aggressive approach can seem villainous.
Ryuko Tatsuma, AKA Ryukyu
Ryukyu has made her way into the top 10 pro heroes, and she is pretty humble about it. Ryukyu has a gentle but firm personality, and while she has a colorful and stylish appearance by default, her Quirk form seems much more evil. She is one of those characters who transform upon using their Quirk -- like Jurota Shishida --and Ryuku turns into a massive, scaly dragon.
Dragons are classic villains in folklore and modern fantasy, with their searing fire breath, frightening claws and arrogant attitude. Anyone would be terrified if they saw Ryukyu's draconic form lumbering down the street. Fortunately, this particular dragon has a heart of gold, and she acted as a mentor for Nejire Hado, Ochaco Uraraka and Tsuyu Asui.
Gunhead
Gunhead is a pro hero who can use his Gatling Quirk to create keratin bullets (like fingernails) and fire them rapidly at his enemies. He is also a short-range specialist, using his Gunhead Martial Arts style to take down villains up close. Not long after the U.A. sports festival, Ochaco Uraraka accepted an internship with this pro hero and learned much from him.
Amusingly, Gunhead has a gentle and cheery personality, despite his criminal looks, and he even teased Ochaco a bit. Gunhead's helmet, punkish attire and scary gloves all make him look villainous, but fortunately, Gunhead's villainy is only skin-deep. In combat, he's no punk; he takes punks down instead.