Master Planner (Dr. Otto Gunther Octavius)

Gender: ♂
Alias of: Doctor Octopus (Otto Octavius)

Master Planner (II)
Master Programmer (Dr. Otto Gunther Octavius)

Gender: ♂
Alias of: Doctor Octopus (Otto Octavius)

Master Weaver (Karn) (Earth-1)
Mastermind (Martinique Jason)
Mastermind (Martinique Jason) (Earth-11326)

Gender: ♀
Alternate version of: Mastermind (Martinique Jason)
Universe/Dimension/Timeline: Earth-11326 (Age of X)

Mastermind (Jason Wyngarde)
Mastermind (II)
Mastermind Excello (Amadeus Cho)
Alicia Masters
Ken Masters
Masters of Evil (I)
Masters of Evil (II)
Masters of Evil (III)
Masters of Evil (IV)
Masters of Menance
Masters of Silence
Masters of Terror
Eric Kevin Masterson
Marcy Masterson
Mastodon
Matador (Manuel Eloganto)
Match (Ben Hammil)
Maul

Gender: ♂
Member of: Order (II)

Mauler (Turk Barrett)
Mauler (Brendan Doyle)
Mauler (Aaron Soames)
Mauvais (Jean-Pierre)
Maverick (Christopher Bradley)
Maverick (Sergeant David North)
Mavericks
Max
Maxam (Maxam)
Luna Maximoff
Maximus (Maximus Boltagon)
Maxxon
Melinda May
Dr. Margaret Mayfair

Gender: ♀
Member of: Project: PEGASUS

Mayhem (Brigid O'Rielly)
Mayhem (April Parker) (Earth-982)

Gender: ♀
Clone/Copy/Impersonator of: Spider-Girl (May Parker) (Earth-982)
Universe/Dimension/Timeline: Earth-982 (M2)

Features
Official Handbook of the Marvel Universe A to Z Update 5.FT

Mayhem Organization
Maymee Hazzit
Mayor (ImageU)
Meredith McCall
Kate McClellan

Gender: ♀
Member of: Knights of Pendragon

Henry P. McCoy (Earth-58163)

Gender: ♂
Alternate version of: Beast (Henry McCoy)
Universe/Dimension/Timeline: Earth-58163 (House of M)

Casey McKann
Ian McNee
Heather McNeil
Harold Meachum
Mean (Earth-5311)

Gender: ♂
Alternate version of: Wolverine (James Howlett)
Universe/Dimension/Timeline: Earth-5311 (Kitty's Fairy Tale)

Features
Wolverine Encyclopedia 2.FT

Meanstreak (Henri Huang)
Meatmarket

Member of: Lilin

Mechamage
Mechano
Medusa (Medusalith Amaquelin Boltagon)

A.K.A.: Madame Medusa
Created by: Stan Lee, Jack Kirby
Gender: ♀
Alternate version(s): Medusa (Medusalith Amaquelin Boltagon) (Earth-9997)
Apprentice of: Future Foundation
Child(ren): Ahura (Ahura Boltagon)
Individual of: Inhumans (I)
Member of: A-Force (II), Fantastic Four (I), Frightful Four (I), Lady Liberators (I), Royal Family of the Inhumans
Parent(s): Ambur, Quelin
Relative(s): Gorgon (I), Karnak (I), Maximus (Maximus Boltagon), Triton (I)
Sibling(s): Crystal (Crystalia Amaquelin Maximoff)
Spoof(s): Mod-dusa (WhatThe)
Spouse(s): Black Bolt (Blackagar Boltagon)

Main
Beyond! 1 - 6
Beyond (HC) 1
Beyond TPB 1
I ♥ Marvel: Marvel Ai 1
Inhumans TPB: Beware the Inhumans 1
Marvel Masterworks: The Inhumans (HC) 1
Marvel Super-Heroes (II) 15
Mighty Marvel: Women of Marvel TPB 1
Women of Marvel 1
Women of Marvel 1

Cameo
The Last Fantastic Four Story 1

Features
Avengers Now! 1.FT
Avengers Strikefile 1.FT
Essential Fantastic Four 4.FT, 6.FT
Essential Official Handbook of the Marvel Universe 1.FT
Essential Official Handbook of the Marvel Universe Deluxe Edition 2.FT
Essential The Official Handbook of the Marvel Universe Master Edition 2.FT
Fantastic Four (III) 3.FT
Fantastic Four Annual (I) 5.FT, 14.FT
The Marvel Comics Index (G&T Enterprises) 4.FT
Marvel Fanfare (I) 38.FT, 45.FT
Marvel Illustrated: Swimsuit Issue 1.FT
Marvel Knights Sketchbook (Wizard Publication) 1.FT
Marvel Swimsuit Special 2.FT - 3.FT
The Official Handbook of the Marvel Universe 7.FT
The Official Handbook of the Marvel Universe Deluxe Edition 8.FT
The Official Handbook of the Marvel Universe Master Edition 24.FT
Official Handbook of the Marvel Universe: The Women of Marvel 2005 1.FT
Thanos Sourcebook 1.FT
War of Kings: Who Will Rule? 1.FT
Women of Marvel 1.FT

Medusa (Medusalith Amaquelin Boltagon) (Earth-9997)

Gender: ♀
Alternate version of: Medusa (Medusalith Amaquelin Boltagon)
Universe/Dimension/Timeline: Earth-9997 (Earth X)

Features
Earth X Sketchbook 1.FT