The octopus was renowned in Graeco-Roman thought for being a master of visual imitation insofar as it could imperceptibly mimic rocks by changing the colour of its skin. What did it mean, then, for the Greeks and Romans to imitate nature’s consummate imitator in art? This article takes two sets of artefacts that featured octopuses – Greek red-figure ‘fish plates’ and Roman ‘fish mosaics’ – and contextualises them alongside Greek and Latin poetry, biology, and philosophy to explore the self-reflexivity of picturing polyps in Graeco-Roman culture. In establishing the octopus as mise-en-abyme, the article salvages the sophisticated self-referentiality of the marine ‘still life’ and recovers a more ecologically grounded way of understanding the relation between art and nature than is traditionally associated with classical art history. Ultimately, seeing the self-consciousness of these octopodal artworks entails becoming more self-aware of ourselves and our place in the world at this juncture of climate crisis.