The coconut octopus, blue ring octopus, Wunderpus photogenicus, day octopuses

Reef octopus and day octopuses in the Ocean Channel Day octopuses, Octopus cyanea (Gray, 1849), aka Cyane’s octopus or big blue octopuses, are large octopuses, with bodies to at least 16 cm and arms to at least 80cm. They are typically brown in color but have the ability to rapidly change color and skin texture.
Wunderpus photogenicus, the wunderpus octopus, is a small-bodied species of octopus with distinct white and rusty brown coloration. 'Wunderpus' from German “wunder” meaning ‘marvel or wonder’.
Due to the appearance and behavior of the wunderpus, it is frequently confused with its close relative, the mimic octopus.
The coconut octopus, alternatively known as the veined octopus, is an intelligent cephalopod widespread in the Indo-Pacific tropical waters.
Blue-ringed octopuses spend most of their time hiding in crevices while displaying effective camouflage patterns with their dermal chromatophore cells. Like all octopuses, they can change shape easily, which helps them to squeeze into crevices much smaller than themselves.