Vava to Vile (changed to not get sued by Lucasfilm, since he already looks enough like Boba Fett as he is)
Sagesse to Serges
Violent to Violen
Vajurila FF (a vajra is a ceremonial item in Buddhism, Hinduism, and Jainism) to Bit (the smaller of two standard units of computer data)
Mandarela BB (named after the mandala, a circular ritual symbol in Buddhism and Hinduism) to Byte (the larger of two standard units of computer data)
Irregular to Maverick
Irregulars/Mavericks from the original X
Launcher Octopuld to Launch Octopus
Icy Penguigo to Chill Penguin
Burnin' Noumander to Flame Mammoth
Sting Chameleao to Sting Chameleon
Spark Mandriller to Spark Mandrill
Storm Eagleed to Storm Eagle
Armor Armarge to Armored Armadillo
Boomer Kuwanger is the same in both regions, though renamed Boomerang Kuwanger in the remake. "Kuwanger" is roughly derived from the Japanese word for stag beetle ("kuwagata"), hence the design.
From X2
Wire Hetimarl to Wire Sponge (actually named after neither the aquatic animal nor the artificial kitchen sink cleaning device, but rather, the luffa or loofa, which is dried for use as a cleaning sponge, which is known in Japanese as "hechima")
Wheel Alligates to Wheel Gator
Bubbly Crablos to Bubble Crab
Flame Stagger to Flame Stag
Metamor Mothmeanos to Morph Moth
Magne Hyakulegger to Magna Centipede
Crystal Mymine to Crystal Snail
Sonic Ostreague to Overdrive Ostrich
From X3
Frozen Buffalio to Blizzard Buffalo
Acid Seaforce to Toxic Seahorse
Screw Masaider to Tunnel Rhino
Electro Namazuros to Volt Catfish
Scissors Shrimper to Crush Crawfish
Shining Tigerd to Neon Tiger
Gravity Beetbood to Gravity Beetle
Explose Horneck to Blast Hornet
From X4
Web Spidus to Web Spider
Cyber Kujacker to Cyber Peacock
Storm Fukurowl to Storm Owl
Magmard Dragoon to Magma Dragoon
Frost Kibatodos to Frost Walrus
Jet Stingren to Jet Stingray
Slash Beastleo to Slash Beast
Split Mushroom is the same in both regions.
From X5 - everyone's named after a member of the band Guns N' Roses. According to the Mega Man wiki: "This name localization was brought about by Alyson Court (voice of Claire Redfield from Resident Evil, another Capcom franchise), in tribute to her then-husband, Erik Suzuki, who was a fan of said band." All of these name changes were undone for the Mega Man X Legacy Collection, some mavericks regaining their original names, others receiving new ones entirely.
Crescent Grizzly to Grizzly Slash, then back
Volt Kraken to Squid Adler, then back
Shining Hotarunicus to Izzy Glow to Shining Firefly
Tidal Makkoeen to Duff McWhalen to Tidal Whale
Spiral Pegacion to The Skiver to Spiral Pegasus
Spike Rosered to Axle The Rednote Ironically, a canon "Axl" would be introduced later on, working for someone named Red, no less, then back
Dark Necrobat to Dark Dizzy, then back
Burn Dinorex to Mattrex, then back
X6 only changes one boss's name (Shieldner Sheldon to Shield Sheldon). The next two entries resumed the tradition.
From X7
Hell Ride Inobusky to Ride Boarski
Tornado Debonion to Tornado Tonion
Wing Karasting to Wing Crowrang
Snipe Ariquick to Sniper Anteator
Burnishing Gangaroon to Vanishing Gungaroo
Splash Warfly, Soldier Stonekong and Flame Hyenard all kept their names in both regions.
From X8
Optic Sunflowerd to Optic Sunflower
Gravitate Antonion to Gravity Antonion
Dark Neid Kamakill to Dark Mantis
Giga Volt Dokuragen to Gigavolt Man-O-War (rendered as "Gigabolt Man-O-War" on his splash screen)
Burn Kokekokker to Burn Rooster
Ice Snow Yetinger to Avalanche Yeti
Earth Rock Trilovich to Earthrock Trilobyte
Bamboo Pandamonium remained the same.
Some of the boss weapons had their names changed too:
Serpent (the company, not the character) to Slither
Life Metal to Biometal
Model V to Model W
Falseroid to Pseudoroid
R.O.C.K. (Rebirth Of Crystallised Knowledge) System to M.E.G.A. (Meta-Encapsulated Granule Awareness SYSTEM) System
Rock-On to Megamerge
Advent, unlike the original ZX where the Pseudoroid names were left unchanged, did this for every Pseudoroid aside from Bifrost the Crocoroid and Argoyle & Ugoyle the Shisaroids.
Dearburn the Gazeroid to Buckfire the Gaxelleroid
Chronophos the Tridenroid to Chronoforce the Xiphosuroid
Rosepark the Floweroid to Rospark the Floroid
Condorock the Vulturoid to Vulturon the Condoroid
Kaisemine the Wasproid to Queenbee the Hymenopteroid
Tesrat the Hedgeroid to Hedgeshock the Erinaceroid
Ijuuin Enzan to Chaud Blaze (apparently, the dubbers misinterpreted his Last-Name Basis)
FireMan to TorchMan
ColoredMan to WackoMan
ColdMan to FridgeMan
AquaMan to SpoutMan (coincidentally, this was later his name in Battle Network 6 to avoid the inevitable legal issues with DC Comics. This was later undone for Mega Man Battle Network Legacy Collection)
