| Mercadia's Downfall | MMQ-205 |
| Merchant of the Vale // Haggle | ELD-131 |
| Merciless Executioner | FRF-76 |
| Merciless Resolve | SOI-123 |
| Mercurial Chemister | RTR-180 |
| Mercurial Geists | EMN-186 |
| Mercy Killing | SHM-231 |
| Meren of Clan Nel Toth | C15-49 |
| Merfolk Looter | DDT-10 |
| Merfolk Mistbinder | RIX-164 |
| Merfolk of the Pearl Trident | POR-60 |
| Merfolk Seastalkers | ZEN-55 |
| Merfolk Thaumaturgist | PLC-56 |
| Merfolk Trickster | DOM-56 |
| Meria's Outrider | DMU-138 |
| Merrow Harbinger | LRW-73 |
| Mesa Unicorn | DOM-27 |
| Mesmeric Fiend | TOR-69 |
| Messenger Jays | CN2-35 |
| Metallic Rebuke | AER-39 |
| Metalspinner's Puzzleknot | KLD-221 |
| Metathran Elite | UDS-38 |
| Meteor Golem | M19-241 |
| Meteorite | ORI-233 |
| Metropolis Sprite | M20-66 |
| Miasmic Mummy | AKH-100 |
| Michiko Konda, Truth Seeker | SOK-19 |
| Midnight Clock | ELD-54 |
| Midnight Guard | BBD-99 |
| Might of Old Krosa | TSP-204 |
| Might of the Masses | ORI-188 |
| Mighty Leap | M19-28 |
| Migratory Route | CM2-161 |
| Mikaeus, the Unhallowed | UMA-106 |
| Mila, Crafty Companion // Lukka, Wayward Bonder | STX-153 |
| Military Intelligence | M15-69 |
| Militia Bugler | 2X2-19 |
| Millikin | EMA-226 |
| Millstone | M19-242 |
| Millstone | M14-213 |
| Mimic | AFR-349 |
| Mimic Vat | C19-219 |
| Mina and Denn, Wildborn | OGW-156 |
| Minamo, School at Water's Edge | CHK-279 |
| Mind Bend | MIR-77 |
| Mind Funeral | MMA-181 |
| Mind Rake | MH1-96 |
| Mind Rot | W16-7 |
| Mind Sculpt | M15-70 |
| Mind Shatter | MM3-77 |