Cleon
Legend
I notice that the Cassowaries Wikipedia entry says "They are good swimmers, crossing wide rivers and swimming in the sea."
Should we do something with that?
After thinking it over, I wouldn't bother.
Elephants are good swimmers who cross rivers and swim in the sea and 5E doesn't bother doing anything with it, so why do something with a cassowary's swimming ability.
Most animals are decent swimmers, D&D tends to only bother if they live in water or can swim all day or night before they need to return to land.