Octopus is an eight-armed, soft-bodied cephalopod mollusc — the common octopus is the classic eating species — famous both for being one of the most intelligent invertebrates on Earth and for a firm, lean, mild-sweet and briny flesh. That flesh is notoriously temperamental: rushed over heat it turns to rubber, but frozen first and then simmered slowly or long-braised it becomes meltingly tender, which is why octopus anchors dishes from Galician pulpo a la gallega to Japanese tako sushi and Greek and Italian grills.