M-308 Gunner

Magic Man (Mega Man boss)

Magic: The Gathering Sorceror

Magi Golem

Magi Skeleton

Magnet Man

Magneto

Magnus

Magus (Chrono Trigger)

Majin Buu

Mallow

Mammoth (Thrill Kill)

Mammoth MKII

Marco

Marcus

Marcy (Chrono Cross)

Marina

Mariner

Mario

Marionette Owl

Marle

Marukka (Thrill Kill)

Master Hand

Master Higgins

Master of Dark Flame

Master Roshi

Matriarch (Queen hero)

Maxim (Lufia)

Maxi-man (Rifts)

Max Steiner (Mutant Chronicles: Doom Troopers, a SNES game)

Maya (K.I.)

Maya (Septerra Core)

M. Bison

Mega Man

Mega Man X

Megatron (Beast Transformers)

Meltdown (KI)

Metal Man (Mega Man boss)

Metal Mario

Mewtwo

Mickey Scymon (U.N. Squadron)

Mike (Startropics)

Mike the Ghoststalker

Minos XIII

Minos XIV

Mitch Hunter (Mutant Chronicles: Doom Troopers, a SNES game)

MLBS (Multiple Laser Battery System)

Mojo (Chrono Cross)

Mojo (Starcraft)

Moldorm

Moltres

Morpha

Mother Brain (CT)

Mother Brain (Metroid)

Motaro (MK)

Mousse (the Matrix)

Mr. Sinister

Mutilator (Bio F.R.E.A.K.S .)

Mysterio (Marvel)

Myukus