According to Austin Whittall at Patagonian Monsters, Tito Bahamonde and his wife Amandina Velázquez live near southern Chile's Lake Vidal Gormaz and have seen a “‘monster’ that supposedly lives in the lake.”
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Patagonian Monsters: Creatures at the Reloncavi Fjord area
This creature is one among many which Aquabeasties found at Austin Whittall's wonderful Patagonian Monsters site.