In the Netherlands, in the province of Limburg, there is the local belief of a vampiric water creature that lives off the blood of children. De Man Met De Haak (“the man with the hook”) is a small, ugly, black-skinned being that lives in ponds and other sorts of waterways. It has a beard made of water plants and webbed feet like a frog. With its hook, it waits for a child to pass near enough for it to lash out, hook it, and pull it down into the water, drowning him. It is a matter of opinion as to whether the De Man Met De Haak drains the blood from its victim while it is drowning or after.

Source: Anon, English Fairy Tales, 159-160