There are at least 5 comic book companies I could name right now, each of them at least 900.
But what the hey, here's Marvel:
3
3-D Man
A
Abyss
Aegis
Aero
Agent (Rick Mason)
Agent X (Nijo)
Agent Zero
Aginar
Aguila (Alejandro Montoya)
Ajak
Ajaxis
Albion (Peter Hunter)
All-Winners Squad
Alpha Flight
Americop
Amphibion
Anarchist
Angel (Angel Salvadore)
Angel Dust
Annalee
Anole
Ant-Man (Scott Lang)
Ape
Arabian Knight (Abdul Qamar)
Araña (Anya Corazon)
Archangel
Arsenic (and Old Lace)
Atlas (Erik Josten)
Atum
Aurora
Avengers
Awesome Andy
B
Balder
Banshee
Baron Zemo (Helmut Zemo)
Battering Ram
Battlestar
Beak
Beast
Bedlam (Jesse Aaronson)
Beetle (Joaquim)
Beetle (Leila Davis)
Beetle (MK-II)
Beetle (MK-III)
Beetles
Beta Flight
Beta Ray Bill
Big Bertha
Big Hero 6
Bishop (Lucas Bishop)
Black Archer (Earth-712)
Black Bolt
Black Cat
Black Knight (Dane Whitman)
Black Knight (Sir Percy of Scandia)
Black Panther (T'Challa)
Black Widow (Natasha Romanova)
Blacklash (unrevealed)
Blade (Eric Brooks)
Blazing Skull (Mark Todd)
Blindfold
Bling!
Blizzard (Donald Gill)
Bloke
Bloodstone, Elsa
Bloodstone, Ulysses
Blue Eagle (Earth-712)
Blue Shield
Bluebird (Sally Avril)
Box (Roger Bochs)
Bradley, Isaiah
Brandon, Moira
Brother Voodoo (Jericho Drumm)
Bruiser (Molly Hayes)
C
Cable
Cage, Luke
Caliban
Callisto
Cannonball (Sam Guthrie)
Captain America (Bob Russo)
Captain America (Roscoe)
Captain America (Scar Turpin)
Captain America (Steve Rogers)
Captain Britain (Brian Braddock)
Captain Marvel (Mar-Vell)
Captain Universe
Catiana
Chamber
Changeling
Cheney, Lila
Citizen V (John Watkins III)
Citizen V (John Watkins)
Citizen V (Paulette Brazee)
Clea
Cloak
Cole, Kasper
Collective Man
Colossus (Piotr Rasputin)
Commando (Frank Bohannan)
Cooper, Valerie
Corsair
Crystal
Cyclops (Scott Summers)
Cypher (Douglas Ramsey)
D
Dagger
Daredevil (Matthew Murdock)
Darkhawk
Darkstar
Darwin
Dazzler (Alison Blaire)
Dead Girl
Deadpool
Deathlok (Luther Manning)
Deathlok (Michael Collins)
Debrii
Demolition Man
Destroyer (Roger Aubrey)
Devil-Slayer
Diamond Lil
Diamondback (Rachel Leighton)
Dinah Soar
Doc Samson
Doctor Druid
Doctor Spectrum (Earth-712)
Doctor Strange (Stephen Strange)
Domino (Neena Thurman)
Doop
Doorman
Drax
Dust
E
Earth Force
Earth Lord
Echo (Maya Lopez)
E cont.
Elektra
Elixir
Empath
Erg
Ernst
Eternals
Excalibur
Exiles
F
Falcon (Carl Burgess)
Falcon (Sam Wilson)
Fantastic Four
Fantomex
Firebird
Firestar
First Line
Fixer (Paul Norbert Ebersol)
Flatman
Flex
Force Works
Forge
Fury, Nick
G
Gabriel, Devil-Hunter
Gambit
Gateway
Gazer
Generation X
Ghost Rider (Daniel Ketch)
Ghost Rider (John Blaze)
Gilgamesh
Gladiator (Kallark)
Goliath (Bill Foster)
Gorgon (Inhuman)
Gorilla Man (Kenneth Hale)
Grasshopper (Doug Taggert)
Gravity (Greg Willis)
Great Lakes Avengers
Green Goblin (Phil Urich)
Greystone
Guardian (James Hudson)
Guardians of the Galaxy
H
Harrier
Havok
Hawkeye (Clint Barton)
Hawkeye (Kate Bishop)
Haywire (Earth-712)
Hellcat (Patricia Hellstrom)
Hellion
Hepzibah
Hercules (Heracles)
Heroes for Hire
Howard the Duck
Hulk (Bruce Banner)
Human Top (Bruce Bravelle)
Human Torch (Jim Hammond)
Human Torch (Johnny Storm)
Husk
Hybrid (Scott Washington)
Hyperion (Earth-712)
I
Icarus (Jay Guthrie)
Iceman
Ichiki, Hisako
Ikaris
Illuminati
Imperial Guard
Impulse (Psionex)
Inhumans
Invaders
Invisible Woman
Iron Fist (Danny Rand)
Iron Lad
Iron Man (Anthony Stark)
Isis
J
Jack of Hearts
Jeffries, Madison
Jocasta
Johnson, Daisy
Jolt (Hallie Takahama)
Jones, Jessica
Jones, Rick
Joseph
Josiah X
Joystick
Jubilee
Juggernaut (Cain Marko)
Junta
Justice (Vance Astrovik)
K
Ka-Zar (David Rand)
Ka-Zar (Kevin Plunder)
Kane, Garrison
Karma
Karnak
King, Hannibal
Knight, Misty
Knights of Pendragon
Korg
Kylun
L
League of Losers
Leech
Leir
Lifeguard
Lionheart
Litterbug
Living Lightning
Living Mummy
Loa
Lockheed
Lockjaw
Longshot
Lucy In The Sky
M
M (Monet St. Croix)
MACH-IV
Machine Man
Madame Web
Maddicks, Artie
Maggott
Magik (Amanda Sefton)
Magik (Illyana Rasputin)
Magma
Mancha, Victor
Mantis
Marnot
Marrow
Marvel Boy (Robert Grayson)
Marvel Girl (Rachel Summers)
Masters, Alicia
Match
Medusa
Meggan
Mercury (Cessily Kincaid)
Microbe
Micromax
Midnight Sons
Miller, Layla
M cont.
Mimic (Calvin Rankin)
Misfit
Mister Fantastic
Mister Immortal
Mister M
Mockingbird
Molten Man
Monkey Joe
Moon Knight
Moondragon
Moonglow (Arcanna Jones) (Earth-712)
Moonstar
Moonstone (Karla Sofen)
Morbius
Moy, Alyssa
Ms. Marvel (Carol Danvers)
Multiple Man
N
Namorita
Nemesis (Jane St. Ives)
New Mutants
New Warriors
Night Thrasher
Nightcrawler
Nighthawk (Kyle Richmond)
Nixon, Kiden
Nocturne (Talia Wagner)
Nomad (Jack Monroe)
North, Dakota
Northstar
Nova (Frankie Raye)
Nova (Richard Rider)
Nuit, La
Nuke (Earth-712)
O
Onyxx
Outlaw (Inez Temple)
Outlaws
P
Paladin
Patriot (Elijah Bradley)
Persuasion
Phat
Phoenix (Jean Grey)
Photon (Genis-Vell)
Pixie (Megan Gwynn)
Plantman
Polaris
Portal
Power Princess (Earth-712)
Prodigy (David Alleyne)
Prodigy (Ritchie Gilmore)
Professor X
Prowler (Hobie Brown)
Pryde, Kitty
Psylocke
Puck (Eugene Judd)
Puck (Zuzha Yu)
Puma
Punisher (Frank Castle)
Q
Quark
Quasar (Wendell Vaughn)
Queen Divine Justice
Quicksilver
Quill (Maxwell Jordan)
R
Radioactive Man (Chen Lu)
Radius
Rage
Rambeau, Monica
Random
Red Guardian (Alexei Shostakov)
Redeemers
Redstone (Earth-712)
Reilly, Ben
Rhodes, James
Richards, Franklin
Ricochet (Johnny Gallo)
Riordan, Dallas
Rocket Racer
Rockslide
Rogue
Roko the Amazing
Runaways
S
S.H.I.E.L.D.
S.T.A.R.S.
Sabra
Sage
Sasquatch (Walter Langkowski)
Satana
Scarlet Witch
Scarlet Witch (Ultimate)
Scorpion (Carmilla Black)
Sentinels
Sentry (Robert Reynolds)
Sersi
Shamrock
Shang-Chi
Shanna The She-Devil
Shape (Earth-712)
Shard
Shatterstar
She-Hulk
Shroud
Silent Fox
Silver Sable
Silver Surfer
Silverclaw
Siryn
Skin
Skyhawk
Skylark (Earth-712)
Slapstick
Sleepwalker
Slingers
Smith, Tabitha
Smuggler (Conrad Josten)
Snowbird
Solo
Songbird
Specter
Speedball (Robert Baldwin)
Spider-Man (Peter Parker)
Spider-Woman (Jessica Drew)
Spider-Woman (Julia Carpenter)
Spider-Woman (Mattie Franklin)
Spirit of '76
Spitfire
Squadron Supreme (Earth-712)
Squid-Boy
Squirrel Girl
Star Masters
Starfox
Stature
Stepford Cuckoos
Stingray
Stonewall
S
Storm
Storm, Franklin
Strong Guy
Sub-Mariner
Subbie
Sunfire (Age of Apocalypse)
Sunfire (Shiro Yoshida)
Sunpyre
Sunspot
Super Sabre
Surge (Noriko Ashida)
Sway
Swordsman (Jacques Duquesne)
Synch
T
Talkback (Chase Stein)
Terror
Thing (Benjamin Grimm)
Thing (Ricardo Jones)
Thor (Thor Odinson)
Thor Girl
Thunderbird (John Proudstar)
Thunderbird (Neal Shaara)
Thunderbolts
Tigra (Greer Nelson)
Tippy Toe
Topaz
Toro (Thomas Raymond)
Toxin
Trance
Triathlon
Triton
U
U-Go Girl
U.S.Agent
Union Jack (Brian Falsworth)
Union Jack (Joseph Chapman)
Union Jack (Montgomery Falsworth)
Ursa Major
V
V-Battalion
Valkyrie
Vampire By Night
Vampire Hunters
Vanguard
Vector
Vindicator (Heather Hudson)
Vision
W
Wallflower
Wanderer
Warlock, Adam
Warpath
Wasp
Whiplash (unrevealed)
White Tiger (Angela Del Toro)
Whizzer (Earth-712)
Wiccan
Wicked
Wild Child
Wild Child (Age of Apocalypse)
Wild Pack
Will-O'-The-Wisp
Wind Dancer
Wind Warrior
Windshear
Wingfoot, Wyatt
Wisdom, Peter
Wither
Wolf Cub
Wolfsbane
Wolverine (James Howlett)
Wonder Man
X
X-23
X-Corporation
X-Factor
X-Factor Investigations
X-Force
X-Man
X-Men
X-Statix
X-Treme
Xavier Security Enforcers
Y
Yellowjacket (Henry Pym)
Yellowjacket (Rita DeMara)
Young Allies
Young Allies (Counter-Earth)
Young Avengers
Young Gods
This includes teams.
This is one company, and incomplete!
Not a great question, but hey, creative nonetheless.