Are there ever any animals featured that aren't Pokémon? Out of the Pokémon episodes that I have seen, I do not remember ever seeing an animal that wasn't a Pokémon. I have also not heard of animals being present in Pokémon.

Which lead me to wonder: Are there ever any animals that aren't Pokémon present in any episode or Pokémon manga?
In Gastly's Pokédex entry for Fire Red it states 


  a being that exists as a thin gas. It can topple an Indian elephant by enveloping the prey in two seconds.


Fish are also seen in the episode Pokémon Shipwreck: