A daeodon skeleton, a possible explanation.
The fisher pig or swamp pig was a cryptid pig reported from Hungary.
Description[]
Said to have died out by the 1880s and 1890s, it was described as a very big animal with a curved back, which lived in large herds in the marshes around the Rivers Tisza and Körös, feeding on crabs and fish instead of vegetation. Orosz István, who first bought the traditional belief in fisher pigs to attention, feels that it was likely just a local variety of wild boar (Sus scrofa), and Tötös Miklós suggested that they may have been feral domestic pigs: Karl Shuker notes that boars and pigs are known to inhabit swamps and marshes, and even to eat fish and marine invertebrates. However, Shuker also questions why such a familiar species would be considered a seperate animal by local shepherds.
A less plausible theory is that they were surviving entelodonts: Karl Shuker notes that "it seems highly unlikely that such conspicuous creatures as entelodonts could have survived into modern times in Europe without having attracted very appreciable, sustained attention from the sporting fraternity, for whom they would have made extremely noteworthy targets and thence trophies (i.e. mounted heads, preserved pelts, etc), to be displayed proudly in hunting lodges and country estates across the continent. And yet no such specimens seemingly exist; none, at least, has been brought to public notice so far.".