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This mysteriously "tattooed" fish was caught near Lopez Jaena in the Misamis Occidental province of the Philippines. Some locals considered the fish a warning from the depths. They're actually right, as the likely non-magical explanation is that the fish was caught in a printed plastic bag floating in the ocean and the pattern transferred to the animal's scales over time. (Mysterious Universe)
According to ABS-CBN, "Zosimo Tano who caught the fish, clarified… that the print on the fish's body came from his shirt, which he used to cover the fish."