Fisch (69)
- O'Mango Goldgrin
- OG 🥺
- Oak
- Oakling
- Oakling Pal
- Oarfish
- Obelisk
- Obsidian
- Obsidian Key
- Obsidian Koi
- Obsidian Lockheart
- Obsidian Salmon
- Obsidian Swordfish
- Obsidian-Bone
- Occultus
- Ocean
- Ocean Hero
- Ocean King
- Ocean Monarch
- Ocean's Champion
- Oceanborn
- Oceanic Tunnel
- Octophant
- Oddie
- Odin's Journey
- Oil Sardine
- Oilfish
- Old Man (Personal Aquarium)
- Old Man (Roslit Bay)
- Oliver
- Olivia
- Ollie Otter
- Olm
- Olmdeer
- Olympian Ascension
- Olympian Core
- Olympian Devil
- Olympian Godbreaker
- Omnithal
- On The Nice List
- Onirifalx
- Onychodus
- Opah
- Opal
- Opalescent Catfish
- Open Ocean
- Oracle Minnow
- Oracle's Eye
- Orange
- Orange Unicycle
- Orc
- Orca
- Orca Boat
- Orca Lantern
- Orca's Demise
- Orcanda
- Orcs Best Friend
- Oreochima
- Original No-Life Rod
- Orion's Trace
- Ornament Fish
- Ornament Ozzie
- Oscar Cichlid
- Oscar IV
- Overclocked
- Owen
- Owen Drift
- Oyster
- Ozark Cavefish
Adopt Me! (37)
- Oakee
- Oakee Cap
- Oakee Knight
- Oakee Wizard
- Ocean Egg
- Ocelot
- Octopus
- Off-Road Car
- Officer Gibbon
- Offroader
- Old King Coal
- Old Sailboat
- Omnisex Pride Pin
- Oni Samurai Hat
- Onza
- Oolong Tea Cup
- Oolong Tea Kettle
- Open Top Speeder
- Orange Backpack
- Orange Betta Fish
- Orange Butterfly
- Orange Glasses
- Orange Hat
- Orange Neon Snowboard
- Orangutan
- Orbital Roller Skates
- Orca
- Orchid Butterfly
- Orchid Racer
- Ornate Horned Frog
- Oryx
- Ostrich
- Otter
- Owl
- Owl Wings
- Owlbear
- Ox