Names to Run Away From Really Fast which inspire fear because they are fearsome adjectives: Vicious, Grim, Sinister, Nefarious, Horrible, etc.
Or they inspire mistrust because they sound "false", like "honest".
The main antagonist of Pokémon 4Ever is named Lord Vicious the Mask (Vicious-sama no Kamen). He's also rumored to have been named for Sid Vicious, but evidence is hazy.
Vishous from J.R. Ward's Black Dagger Brotherhood novels, mercifully shortened to 'V'. Most of her male characters have bizarrely spelled "badass" names, including Torhment, Phury, Zsadist, Rhage, Rehvenge, and Wrath (well, that last one is spelled correctly). John Matthew doesn't fare any better with his warrior name: Tehrror; as does Butch when he's revealed to be a half-breed and gets saddled with a vampiric name of legend: The Dehstroyer.
Sid Vicious of the Sex Pistols. Sid was actually not that violent, nor was he particularly good in a fight; the pose of being a "moral danger" was certainly deliberate.
Shady Shrew from Slylock Fox. This trope is usually extrapolated to other bit criminals like Reeky Rat or Slick Smitty — it's surprising that name profiling hasn't been implemented yet.
Pokemon Colosseum: It may be an unwritten rule that the leaders of Cipher (listed far below) have some part of Evil in their name. First was Evice, and second was Greevil. For added evil points, Greevil's Japanese name translates into 'Deathgold'.
Darth Sidious of Star Wars. Double points for rhyming with "hideous". There is a certain in-story justification, as Sith 'names' are not technically names, but titles given after they've purposely started down the road of evil.
Yami (= Dark) Yugi, whose early punishments for people who attacked or threatened his friends included tricking people into yoyoing themselves through a roof to fall several stories, getting people stung by their own scorpions and subjecting people to illusory torture by Eldritch Abomination.
A common misconception surrounding Star Wars is that Darth is Dutch or German for dark, when neither of these statements are accurate. Dark would be donker and dunkel, respectively. Vader, on the other hand is Dutch for father, though it is pronounced differently in Dutch.
Subtly, several names translate to disabilities, though that's not always bad. On the good side, Cecile from Code Geass ("Blind"). On the bad side, Claudia from The Vampire Chronicles ("Lame"). "Cecile" comes from "caecus", which means "blind" in Latin. In olden times it implied powers of prophesy as well, since many famous seers (Tiresias for example) were blind.
Sgt Gross in the Blake's 7 episode "Moloch" is one of the lesser known villains of the show, but notably nasty.
Mighty Morphin' Power Rangers has Master Vile, Rita Repulsa, her brother Rito Revolto, Maligore (combination of Gore and Malevolent), General Havoc, Dark Specter, Darkonda, Ecliptor, Treacheron, Villamax, Deviot, Furio, Captain Mutiny, Hexuba, Diabolico, Jinxer, Onikage, Toxica/Necronomica, and Mesogog (from Magog, as in "Gog and Magog").
Johnny Rotten (real-life: John Lydon), band leader of the Sex Pistols. Given that 'Johnny' is British slang for 'condom', that verges on squick, too.
Adam Savage from MythBusters: His job involves smashing, blowing up, or otherwise destroying various items in big and spectacular ways (and he is very enthusiastic about his work). Also, in episodes where the crew play out character roles, Adam often plays villainous characters with "Savage" somewhere in their name (i.e. Baron von Savage, Captain Redbeard the Savage).
Colm Meaney an Irish actor who is actually by many accounts a pretty nice guy. Doesn't help that outside of Star Trek fandoms he's mostly known for playing villains or at the very least hard-assed Anti-Hero types.
Ivan the Terrible. He was a good ruler early on, defeating many enemies of the Russians, earning him the nickname which could also be translated as "formidable" or "fearsome". Later on, he became The Caligula, making his name scary but appropriate on a whole different way.
There is is a Zimbabwean footballer (soccer player) called Danger Fourpence.
