O

Obedient

Obliviax

Octopus, Giant

Octopus, Octo-Jelly

Odem

Ogre

Ogre, Half-

Ogre, High

Ogre, Ice Spire

Ogre (Krynn)

Ogre, Mischta

Ogre, Nzunta

Ogre, Stonecrown

Ogre (Zakhara)

Omm-wa

Omshirim

Oni

Ooze/Slime/Jelly I

Ooze/Slime/Jelly II

Ooze/Slime/Jelly, Ghaunadan

Ooze/Slime/Jelly, Slithering Tracker

Ooze Sprite

Ophidian

Opinicus

Orc

Orc, Neo-Orog

Orc, Ondonti

Oread

Ormyrr

Orpsu

Otyugh

Owl

Owlbear I

Owlbear II

Owl, Space