- Mail daemon
- Manes
- Marilith
- Master Assassin
- Master Kaen
- Master lich
- Master of Thieves
- Mastodon
- Medium luggage
- Medusa
- Megatherium
- Minion of Huhetotl
- Minotaur
- Modron duodrone
- Modron monodrone
- Modron pentadrone
- Modron Primus
- Modron quadrone
- Modron quarton
- Modron quinton
- Modron secundus
- Modron tertian
- Modron tridrone
- Monk
- Monkey
- Mountain centaur
- Mountain nymph
- Mucilaginous cube