Leeches

Leeches are found in inland freshwaters as well as in marine waters on all continents except Antarctica.

An excerpt from the article 20 facts about Leeches
They can live in freshwater, brackish water, saltwater, and on land. Leeches prefer shallow, still, or slow-moving water. They are not found in rushing mountain streams or raised bogs. Those adapted to life on land (few) inhabit the litter of tropical forests, such as the Ceylon leech.