SEE UPDATE BELOW
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)
UPDATE:
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.”
(Thanks, Teddy-Bob_Silas!)