Local authorities say Atem Lok Atem was fishing at the Awarpiny fishing area in Bau Luony River that evening when the mammal attacked him.
“The victim of today is the fisherman who used to catch fish there many years ago for his family's survival,” said David Atem Matiop, payam administrator.
The 36-year-old man sustained injuries to the backside, chest, and arms.
He said the fisherman succumbed to injuries while receiving treatment at a local health facility.
There have been similar reported attacks by hippos in the county and adjacent areas.
Col. Atem Marac Mawien, Inspector General for the Wildlife Department in Warrap State, commented on the incident, saying there is nothing the government can do about the recurring hippo attacks.
Instead, he encouraged fishermen to always protect themselves from the animals.