The Dark Cures in The Movie of Yes! Precure 5 switch out the protagonists' bows and pastels for dark colours and angular, even pointy accents on their clothing. (Amusingly, Cure Rouge's counterpart apparently missed the "dark colors" memo and looks like a sharper-edged version of Cure Rouge.) The real Precure 5, in contrast, gets a Frilly Upgrade.
The Zeons from Mobile Suit Gundam. The massproduced Zaku II mobile suit used by the Mooks as well as the limited production Gouf have spiked Shoulders of Doom as one of their most memorable features. This starts to thin out towards the end of the series as the aging Zakus are replaced by the more powerful Rick Doms & Gelgoogs (both spike-free, though the latter do have rather pointy shoulders). This trope shows up now and then in later Gundam shows, especially if they feature a mobile suit that is an Expy of the Zaku.
Eris from Slayers once only wore free-flowing and modest robes. That was until her Face-Heel Turn, whereupon she promptly dons Spikes of Villainy.
Naga the White Serpent has shoulder guards with Awesome, but Impractical Spikes of Villainy; a Running Gag in the OVA has her stabbing herself in the face each time she raises her arms to cast Freeze Arrow.
Some of the low level akuma in D.Gray-Man have lots of spikes sticking out of them.
Hiruma from Eyeshield 21 has a very pointy appearance overall, from his hair to his ears to his fangs. Even his nose is pointy. The idea was to give him a demonic appearance. It works.
In Naruto, Pain has a bunch of spiky piercings in his face. There's also the ones in the faces of all his other bodies. They are made of special materials that act as receivers controlling said bodies from a remote location.
Trigun's Omnicidal Maniac Legato Bluesummers has spikes on one shoulder - and a freaking skull on the other. Just 'cause that's how he rolls.
The Shredder in Teenage Mutant Ninja Turtles. The weapons were conceived when someone wondered what it would be like to have cheese graters on their arms. (Whether the armor was actually functional as a weapon or whether it was just ornamental depended on the continuity; in some versions, it was just for show, and he used standard archaic weapons like swords most of the time, while in others, the armor was indeed useful as an offensive weapon.)
Ghost Rider is often depicted with small spikes, as benefits an Anti-Hero biker. In contrast, his Evil Knockoff Vengeance has two-foot shoulder spikes and a spike mohawk growing out of his Flaming Skull. He's also been known to intentionally impale victims on his shoulder spikes.
Godzilla both uses and subverts this one: the man himself is fairly spiky, and ranges from Bad Ass villain to Bad AssAnti-Hero to child-friendly Super Hero. Anguiras, the spikiest monster of all, is almost always good and functions as Godzilla's Sidekick at times. Gigan, meanwhile, is always evil, has spikes for hands, a spike on his head, spiky wings, and a buzzsaw in his stomach. And Big Bad King Ghidorah is only slightly spiky.
SpaceGodzilla, Godzilla's evil clone from Godzilla vs. Space Godzilla, has two massive spikes on his shoulders, a crown-like spike on his head, and several small spikes at the tip of his tail.
Nero's◊ ship◊ in the Star Trek reboot. Ironically, the ship is a simple mining vessel in its original time period.
Even the Narada's torpedoes are spiky. Nero really liked spikes.
Note that the prequel comic indicates that the Narada didn't look like that until Nero outfitted it with prototype hybrid Romulan-Borg technology in his quest for revenge.
Transformers in the movie series seem to have a lot of spikes. Although both Autobots and Decepticons have them, Decepticons seem to have more (and Megatron is made up of precious little but spikes).
In The Lord of the Rings, after the Witch-King moved into the fortress of Minas Morgul, he evidently did some redecorating, 'cause the place looks like the Minas Tirith (good guys) fortress with — you guessed it — gigantic spikes bolted on. There's also Sauron himself, who is kitted out in armour that can only be described as spiketacular. The Black Gates, Barad-dûr and Orthanc (modified by Saruman to resemble Barad-dûr) also fall into this, to an extent that if you fell off the top of them you'd think you'd be more likely to die by impalement than by hitting the ground.
Pinhead in the Hellraiser series has a face full of spikes (well, nails).
The Shredder in the live action Teenage Mutant Ninja Turtles films has spikes on his outfit, as well as on him, that spring up after being doused in chemicals. Tokka the mutant snapping turtle has spikes, but is less evil and more... dumb and gullible.
Most of the dragons in How to Train Your Dragon combine this with lots and lots of sharp, spiky teeth. In an interesting twist, the fastest, most maneuverable, and arguably the deadliest one, Toothless the Night Fury, forgoes the spikes for a more streamlined look. Not surprisingly, he's the first sympathetic dragon that the viewers encounter.
Star Wars' Darth Maul has a number of small devilish horns growing from his head. The rest of his species does not look nearly as manacing without the Sith facial tattoos, but the horns complement it nicely.
Megamind practically lives by this trope. Everything he owns is adorned with spikes - his outfits, his car, his robots, his weapons - even something as mundane as a pair of tongs he owned was adorned with spikes. None of them serve any purpose other than to make things look more "villain-y".
In K.A. Applegate's Animorphs books, the kids have a hard time accepting the fact that unhosted Hork-Bajir are, in actuality, good guys, due to the dangerous-looking blades the cover the Hork-Bajir figure.
In Iain M. Bankss Culture novels, one race of aliens, the Affront, like to adorn their war spaceships with huge spikes and blades.
The Shrike in Dan Simmon's Hyperion Cantos novels is a cryptic three meter tall killing machine constructed of razor-sharp metallic spikes and blades. It's named after a bird that impales its prey on spikes.
Lampshaded in David Eddings's final book of The Elenium trilogy, when they find the temple of the Big Bad guarded by warriors in heavily spiked and hooked armor, which the heroes laugh at - not only would the spikes get in the way of the wearer, they'd also serve to guide sword blows in to weak spots in the armour. It turns out that they were created because the Big Bad was intimidated by the appearance of heavy armor, but did not understand it. Besides, it turns out the guards weren't intended to fight anyway.
The designer of the gun had clearly not been instructed to beat about the bush. 'Make it evil," he'd been told. "Make it totally clear that this gun has a right end and a wrong end. Make it totally clear to anyone standing at the wrong end that things are going badly for them. If that means sticking all sort of spikes and prongs and blackened bits all over it then so be it. This is not a gun for hanging over the fireplace or sticking in the umbrella stand, it is a gun for going out and making people miserable with."
Scourge from Warrior Cats is a cat who wears a collar studded with dog teeth; many cats in his Clan, BloodClan, wear similar collars as well.
Anything to do with the Shadows in Babylon 5. Even their ships all look like big black spiky nightmares...Even their planet-killer, unveiled in season 4, works by firing big spikes from orbit into a planet that then destroy it from the inside out.
Everything in Victory is covered with spikes of some sort... even though the actual game is about perfectly ordinary auto racing.
The tag team The Road Warriors/The Legion of Doom was well known for the spiked shoulder pads they wore as they entered the ring. In fact, these, along with their strangely-painted faces, punk-style hair, and tree-trunk-like builds, made for 100% grade-A Nightmare Fuel for some people. The look stayed intact long after their Heel-Face Turn. They even broke off a spike and stuck it into the eye of Dusty Rhodes.
Psicosis was known to have spiked shoulder pads and wrist bands, in addition to horns.
Daizee Haze refused to MsChif while the latter's spiked vest was anywhere near the ring.
The Midwest Militia's Allysin Kay and Sassy Stephanie have been known to wrestle in spiked sports bras, which make even some of the most basic holds they apply very painful. Kay's Made In Sin, April Hunter and Taylor Made, also used them as did Ivelisse Vélez in Valkyrie.
An orc warlord named King Obould wears spiked full plate. he started as a villain and has since become an Anti-Villain, and possibly a secondary protagonist as well.
There is a prestige class in service to the Chaotic Evil deity Cyric called the Spur Lord, and a few of their abilities are all about making use of the spikes on their armor.
Basic D&D Immortal level module IM3 The Best of Intentions. The Chaotic Evil Immortal NPC villain Hircismus takes the form of a Shaggy Demon. Beneath his long, shaggy hair are short, stiff poisonous spines. He likes to grapple opponents to force them against his spines.
There's also the Cadaver Collector, which might be 'usually' lawful neutral, but given how they're described as golems typically used to collect bodies for their masters, usually for necromancy, chances are not a lot of not a lot of good individuals will construct and command a Cadaver Collector. Notable for actually making use of its spikes in both the fluff and the stats.
There's also the Soulspike Devourer◊. See the big one in the back? Yeah, that's a semi-skeletal Eldritch Abomination with souls impaled on the massive bony spikes coming out of its body. It's an Always Chaotic Evil horror that basically rips souls out of people and causes them immense agony when it shoves them on its spikes. It also consumes said souls for a boost to its power in a pinch. Worst of all, it speaks Common, which means almost anyone can understand it. Kind of makes you miss the barbed devils.
In Mutant Chronicles, the Dark Legion cover their vehicles, firearms, and armor with spikes. Examples include Alakhai the Cunning, Golgotha, and Stahler's One-Winged Angel form.
All of Chaos in Warhammer and Warhammer 40,000. They actually use the spikes on their armor and vehicles to impale the heads of slain foes/victims and eventually make a gruesome trophy rack. At least one Chaos army book has included "Spiky Bits" as a piece of equipment that makes its bearer more effective in combat. That guy up there in the picture? He's a good example.
Also, Da Orcs (or Orks) in both series, but to a lesser extent.
The Dark Elves/Eldar actually use blades instead of spikes, but otherwise have this trope in spades.
The Lizardmen can rival Chaos in the spikes department, though, especially because all of their melee weapons are spiked clubs...though they're notas evil.
Speaking of Orcs, the Horde in Warcraft held onto their spikes even when the race pulled a Heel-Face Turn after the first few games.
In World of Warcraft, some of the Warlock armor sets had spikes on them, which is to be expected as they use the powers of demons. Some of the more morally-neutral classes' armor have them also, as does armor which is not class-specific. They all look cool, but it makes you wonder about Blizzard...
Enthusiastically embraced by City of Heroes with the expanded costume elements added in the release of City of Villains, including all manner of clothing pieces featuring horns, spikes, chains, barbed wire, and other pointy bits. Additionally, one of the Veterans' Rewards badges gives the player access to a special set of high-tech spiky bits.
And ironically enough, these costume parts are equally accessible to heroic and villainous characters.
Walhart of Awakening has thin spikes on his armour, and is a cruel conqueror who wants to take or defeat everything he sees. But if you recruit him, he becomes at least a little bit nicer.
Pokémon Diamond and Pearl 's antagonistic group, Team Galactic, had a headquarters with large Spikes Of Villainy on both sides. (The spikes were white, though.)
Overlord: as you do evil deeds and your Corruption Level rises, you grow spikes and spines all over your body, particularly on the shoulders, which get bigger as your villainy increases. Your Dark Tower follows suit, though you can adorn it with a lot of nifty spiky things even if you stay (relatively) good. If you go evil, it just seems to spontaneously grow them.
Similarly, the tower that acts as your base in Black & White starts out with several flat, blunt rays spreading out from the bottom. As you become more evil, the tower turns black and the rays curl up into wicked spikes.
Jin Saotome from Cyberbots: Full Metal Madness, better known for his Marvel Versus Capcom appearances, is a good guy with spikes on the shoulders of his outfit.
The Shake King in Wario Land Shake It had this, with the standard evil overlord spiked beard (with viking horns), spiked bracelet type things, and the like.
Given how the Dwarves of Dwarf Fortress act at times, it's no wonder that everything they decorate ends up menacing, with spikes of wood or basalt or dwarf bones.
Wolf O'Donnell from Star Fox wore spiked shoulder pads in his later appearances. In Super Smash Bros. Brawl, his claws are almost long enough to count as well.
While not actually a villain, Sonic's Werehog transformation in Sonic Unleashed has spikes on his shoes akin to golf cleats. They actually seem to serve a purpose since they allow him to stop on a dime.
The Final Starman and Starman Deluxe from EarthBound have spiked shoulders and spikes on the top of their heads. The Final Starman and the Starman Deluxe happen to be one of the stronger enemies in the game.
In Fallout 3, one of the Ax-Crazy Raider armors is aptly named "Raider Painspike Armor".
Semi-example would be the Tribal Power Armor and Ashur's Power Armor from Fallout 3's DLC, The Pitt. Highly stylized PA sporting makeshift repair that included a horned cow skull, the Tribal PA doesn't do melee damage like the Painspike does, and for a PA, it has the lowest Defense Rating. However, it does give you +15 AP to be lined up for those satisfying VATS kills.
Hades in God of War has these protruding from his whole body, mainly the back. But he's actually less evil than the other gods, like Zeus or Athena. His sole reason for fighting you is your murder of his loved ones.
The Darkspawn in Dragon Age. Everything they wear or carry around (weapons, shields) is adorned with spikes. They even build spiky altar-like structures wherever they camp and adorn statues from other civilizations with spikes wherever they go. Also, played with in Dragon Age II, where after you meet party member Fenris, Varric warns you that he wears spiky black leather. However, Fenris isn't particularly villainous - just an Anti-Hero with, as Varric puts it, "issues."
Daedric weapons and armor in The Elder Scrolls are all pretty spiky. They are also the trademark equipment of the Dremora, the vicious servitors of Mehrunes Dagon, the daedric Prince of Destruction.
Most of the invading Machines in Mini Robot Wars have spikes on them, but some get more spikes as they get stronger. Smasher (the basic enemy unit) has a stronger version called the Heavy Smasher, which is black and has more health and more spikes. An even stronger version is called the Mega Smasher, which is purple, has more attack power and health, and...even more spikes.
Then there is the Giant, which has an upgraded form called the Titan, which is green, has more health, can pull a One-Hit Kill on THREE of your units instead of just one, and has more spikes.
Dark Souls has the infamous Darkwraith Kirk (though he's actually a Chaos Servant), The Knight of Thorns. His armor set is one of the few examples where spiky armor is actually used in combat, as you can roll into enemies to damage them (it's minimal damage at best, but still). Even his sword is spiky and is the only straight sword in the game which causes bleeding.
In the Halo games, the Hunters had massive spikes on their backs. These were stated in extra material to be razor-sharp, but were never used for combat, and mostly were to make them look cool, and, when they're an enemy, evil.
Command & Conquer: Tiberian Dawn: In the final GDI mission, you're told that Kane's headquarters has finally been located and that it's time to launch a final assault against him. Then you get a good look at the Temple of Nod, with its glowing red lights and spikes emanating from it, and you wonder how anyone could have missed it.
The Head of Square Enix from Super Flash Bros' Decline of Video Gaming flash movie series is merely a person with spiky anime hair, a dress shirt, and random spikes sticking out from under his arms to make him look evil.
In the fantasy spoof comic Nodwick, Yeagar the warrior once bemoans upon an evil adventuring party, "The accessories on their warrior! My spiked shoulder plates are no match for his blade-festooned finery!"
The original design of Avatar: The Last Airbender had Fire Nation characters, especially in regards to Prince Zuko, sport spiky, red armor. This was scrapped and came to receive an internalTake That in the actual series when Sokka mocks the fact that the Water Tribe has Fire Nation uniforms that are almost a century out of date by sproinging the spikes on the shoulders. The current armor still has spikes on the scary masks the Faceless Goons wear, and Aang actually uses one to cut the rope tying his hands after beating the other guards.
Another parody came when the Gaang was in a weapon shop and Aang was wearing a ridiculously large set of armor that even has a spike with a buzzsaw in it. It was even accompanied by a metal riff (which is incredibly out of place in this series). Said costume was included because the merchandisers tried to insist that Aang wear one like that for his battles, despite the fact that it's completely against his fighting style.
Metalocalypse's Dethklok have this kind of design on their vehicles and other accessories. "Dethfone", a cell phone designed by them while drunk, has so many spiky bits that it's almost impossible to use without poking out one's own eye. Murderface uses it to kill a monster.
The Michael Bay live action movies have all Cybertronians spiky and more alien in their pre-Earth forms, and Megs is the one who never takes an Earth vehicle mode. As such, every single inch of the Emperor of Destruction's body is twisted, razor-sharp death.
Transformers Prime: Megatron once again. His robot mode is pre-Earth Animated Megs with some Bayformers touches.
And in Transformers Cybertron. As a result of rebuilding himself with pieces of Unicron's body and absorbing what remained of the dark god's power, he sports demonic horns and numerous spikes. Unicron himself features these.
Jafar from Aladdin gains a spikier-looking outfit after wishing to be "the most powerful sorcerer in the world!" His shoulder pads become larger and pointier, his hat loses its feather and gains two spikes facing either side, and his cobra staff actually opens its mouth.
In Sleeping Beauty, Maleficent actually has spikes covering her dragon form at the end of her film: four on her neck, six on her back, five on the base of her tail, and three on the tip of her tail.
In "Inspiration Manifestation", as if the book hidden behind a wall on a pedestal over a pit weren't suspicious enough, it has these on the cover.
Adventure Time has a particularly literal example of this trope. Ice King, who was the main recurring villain in early seasons, wears a spiky crown. It turns out that said spiky crown is, in fact, the actualvillain — Ice King himself is merely Brainwashed and Crazy by it.