Octopus have been found to be extremely clever- for an invertebrate, and can find their way through complex mazes and they constantly surprise scientists who study them. Octopus, squid and cuttlefish can all change their skin colour and texture which helps them hide in plain view from predators (and their prey) and to communicate with other members of their species.
Generally speaking you would expect to find octopus in water but in the above two images it shows one making its way across a rock shelf from a rock pool (that it was stranded in at low tide) to the ocean 25 m or so away. When I moved in close to photograph it it squirted me three times as I moved around it. It hit me with a jet of water and its aim was spot on no matter if I was in front or behind it. The image was taken at Point Sampson in WA.
This family has a surprising method of self defence. They are able to release projectile darts at anything that handles it or attacks it. The darts have barbs on them and carry toxins. They are normally used to disable its prey. Some are much more dangerous than others. Some tropical species have been responsible for deaths of people. This is a Victorian species and is not considered to be extremely dangerous but it is best not to handle any species of cone shell. These creatures feed at night time so it is easy to avoid them.
This is a Pale-headed octopus, they are found in Victorian waters.
Below are some of the common seasnails in Victoria.
This is a pheasant snail, it is popular with collectors because of its pretty markings. Urqharts Bluff, Vic.