Abdopus aculeatus is a small octopus species in the order Octopoda. A. aculeatus has the common name of algae octopus due to its typical resting camouflage, which resembles a gastropod shell overgrown with algae. It is small in size with a mantle around the size of a small orange (c. 7 cm or 3 inches) and arms 25 cm (10 inches) in length, and is adept at mimicking its surroundings.
A. aculeatus has been described as “the only land octopus”, because it lives on beaches, walking from one tidal pool to the next as it hunts for crab. Many octopuses can crawl short distances on land when necessary, but no others do so routinely.