Real Animals:
* Opossum: A marsupial found in the Americas.
* Opposum: This is a variant spelling of opossum.
* Orangutan: A large ape found in Borneo and Sumatra.
Less Common Animals:
* Opah: A deep-sea fish with a reddish-orange body.
* Opistognathus: A genus of fish called "jawfishes" - these are small, colorful fish that live in the Indo-Pacific region.
Mythical Creatures:
* Ophiuchus: A constellation in the zodiac that is sometimes associated with the serpent-bearer.
* Ophion: A primordial serpent in Greek mythology.
Let me know if you're looking for something specific!