You can catch Carvanha in Pokemon Omega Ruby by sinking his ship.
You can catch Nincada in Pokemon Omega Ruby when in the shed.
You can catch Whismur, the Whisper pokemon, in Pokemon Omega Ruby when it is exhausted.
You can catch Wingull in Pokemon Omega Ruby as it flies in the sky.
You can catch Shroomish in Pokemon Omega Ruby in rotting leaves deep in the forest.
You can catch Sableye in Pokemon Omega Ruby by attacking the red jewel on its chest.
It is in Route 119
You can catch Nincada in Pokemon Omega Ruby when in the shed.
You can catch Whismur, the Whisper pokemon, in Pokemon Omega Ruby when it is exhausted.
You can catch Wingull in Pokemon Omega Ruby as it flies in the sky.
You can catch Slakoth, the Slacker in Pokemon Omega Ruby when it is sleeping.
You can catch Shroomish in Pokemon Omega Ruby in rotting leaves deep in the forest.
You can catch Sableye in Pokemon Omega Ruby by attacking the red jewel on its chest.
You can catch Surskit in Pokemon Omega Ruby in ponds, rivers, and other wetlands.
You can catch Ralts in Pokemon Omega Ruby before it senses your emotions using its horns.
You can catch Seedot in Pokemon Omega Ruby on on routes 203 and 204, in Eterna Forest.
You can catch Feebas in Pokemon Omega Ruby in water, and by learning its evolved milotic form.
Illumise in Pokemon Omega Ruby can be caught in Zorua at the park.