| Maxx "C"Storm of Ragnarok · 086 | Storm of Ragnarok | 086 | Secret Rare | €1.62 |
| Mayakashi MayhemDuel Overload · 056 | Duel Overload | 056 | Ultra Rare | €0.21 |
| Mayakashi MetamorphosisHidden Summoners · 039 | Hidden Summoners | 039 | Super Rare | €0.27 |
| Mayakashi ReturnHidden Summoners · 038 | Hidden Summoners | 038 | Secret Rare | €0.02 |
| Mayakashi WinterDark Neostorm · 057 | Dark Neostorm | 057 | Super Rare | €0.19 |
| Mayhem Fur HireDark Saviors · 025 | Dark Saviors | 025 | Secret Rare | €0.02 |
| Mayosenju DaibakThe Secret Forces · 001 | The Secret Forces | 001 | Secret Rare | €0.56 |
| Mayosenju HitotRising Rampage · 011 | Rising Rampage | 011 | Super Rare | $0.05 |
| Mazera DeVilleAncient Sanctuary · 111 | Ancient Sanctuary | 111 | Secret Rare | $0.40 |
| Mecha BunnyThe Duelist Genesis · 027 | The Duelist Genesis | 027 | Common | $0.11 |
| Mecha-Dog MarronFlaming Eternity · 019 | Flaming Eternity | 019 | Common | €0.22 |
| MechaleonUnlisted Printings | Unlisted Printings | — | — | — |
| MechanicalchaserTournament Pack: 1st Season · 001 | Tournament Pack: 1st Season | 001 | Ultra Rare | €0.20 |
| Mechanical HoundCybernetic Revolution · 018 | Cybernetic Revolution | 018 | Common | €0.07 |
| Mechanical MechanicBurst Protocol · 081 | Burst Protocol | 081 | Common | €0.03 |
| Mechanical SnailMagic Ruler · 021 | Magic Ruler | 021 | Common | $0.04 |
| Mecha Phantom Beast AerosguinJudgment of the Light · 082 | Judgment of the Light | 082 | Ultra Rare | €0.38 |
| Mecha Phantom Beast AuroradonDuel Overload · 017 | Duel Overload | 017 | Ultra Rare | €0.57 |
| Mecha Phantom Beast BlackfalconLord of the Tachyon Galaxy · 023 | Lord of the Tachyon Galaxy | 023 | Common | €0.09 |
| Mecha Phantom Beast Blue ImpalaJudgment of the Light · 023 | Judgment of the Light | 023 | Ultra Rare | €0.11 |
| Mecha Phantom Beast ColtwingJudgment of the Light · 024 | Judgment of the Light | 024 | Common | €0.04 |
| Mecha Phantom Beast ConcorudaJudgment of the Light · 041 | Judgment of the Light | 041 | Super Rare | €0.24 |
| Mecha Phantom Beast DracossackLord of the Tachyon Galaxy · 053 | Lord of the Tachyon Galaxy | 053 | Secret Rare | $0.16 |
| Mecha Phantom Beast HamstratLord of the Tachyon Galaxy · 025 | Lord of the Tachyon Galaxy | 025 | Ultra Rare | $0.12 |
| Mecha Phantom Beast HarrliardJudgment of the Light · 025 | Judgment of the Light | 025 | Common | €0.06 |
| Mecha Phantom Beast JaculuslanWorld Superstars · 034 | World Superstars | 034 | Super Rare | €0.10 |
| Mecha Phantom Beast KalgriffinShadow Specters · 028 | Shadow Specters | 028 | Rare | €0.14 |
| Mecha Phantom Beast MegaraptorLord of the Tachyon Galaxy · 021 | Lord of the Tachyon Galaxy | 021 | Super Rare | €0.22 |
| Mecha Phantom Beast O-LionPrimal Origin · 026 | Primal Origin | 026 | Rare | €0.34 |
| Mecha Phantom Beast RaitenCircuit Break · 030 | Circuit Break | 030 | Common | €0.05 |
| Mecha Phantom Beast Sabre HawkShadow Specters · 027 | Shadow Specters | 027 | Common | €0.06 |
| Mecha Phantom Beast StealthrayLord of the Tachyon Galaxy · 024 | Lord of the Tachyon Galaxy | 024 | Common | $0.05 |
| Mecha Phantom Beast TetherwolfLord of the Tachyon Galaxy · 022 | Lord of the Tachyon Galaxy | 022 | Rare | €0.13 |
| Mecha Phantom Beast TokenOTS Tournament Pack 9 · 026 | OTS Tournament Pack 9 | 026 | Super Rare | €3.69 |
| Mecha Phantom Beast TurtletracerLord of the Tachyon Galaxy Sneak Peek Participation Card · 1 | Lord of the Tachyon Galaxy Sneak Peek Participation Card | 1 | Ultra Rare | $0.13 |
| Mecha Phantom Beast WarbluranJudgment of the Light · 022 | Judgment of the Light | 022 | Rare | $0.15 |
| Mecha Sea Dragon PlesionAbyss Rising · 033 | Abyss Rising | 033 | Common | $0.11 |
| Mech BassUnlisted Printings | Unlisted Printings | — | — | — |
| Mech Mole ZombieUnlisted Printings | Unlisted Printings | — | — | — |
| Mechquipped AngineerNumber Hunters · 035 | Number Hunters | 035 | Super Rare | €0.20 |
| Meda BatLegend of Blue Eyes White Dragon · 083 | Legend of Blue Eyes White Dragon | 083 | Common | €0.02 |
| Medallion of the Ice BarrierStarstrike Blast · 054 | Starstrike Blast | 054 | Common | €0.14 |
| Mediclius the Extraordinary Power PatronBeyond the Brave · 048 | Beyond the Brave | 048 | Ultra Rare | €3.38 |
| Medium of the Ice BarrierDuel Terminal 2 · 018 | Duel Terminal 2 | 018 | Duel Terminal Normal Parallel Rare | €0.09 |
| Medium Piece GolemThe Duelist Genesis · 007 | The Duelist Genesis | 007 | Common | $0.13 |
| Medius the PureDuelist's Advance · 008 | Duelist's Advance | 008 | Ultra Rare | €0.51 |
| Medusa, Watcher of the Evil EyeThe Infinity Chasers · 028 | The Infinity Chasers | 028 | Super Rare | €0.21 |
| Medusa WormThe Lost Millennium · 022 | The Lost Millennium | 022 | Common | €0.26 |
| Mefist the Infernal GeneralDark Crisis · 066 | Dark Crisis | 066 | Rare | €0.10 |
| Mega Fortress WhaleLegendary Duelists: Duels From the Deep · 016 | Legendary Duelists: Duels From the Deep | 016 | Ultra Rare | $0.27 |