So far I have only encountered them on Rag. They tend to follow you out of the water from what I have experienced. They do drain stamina and induce torpor. So either run or kill it. I have explored most of Rags ocean (I only play Rag) and I haven't seen them anywhere else except for in Viking Bay by around the sunken ship. scariest creature to me so far do to it following me out of the water.

More Eurypterid Encountering Tips