The Giant Cuttlefish (Sepia apama) is incredible and easily one of the best things to see in Sydney. They can be seen year round but especially in April and May when they mate.
They are a large cuttlefish up to a metre in length which can be pretty scary sometimes since they can move so fast. Their tentacles can be almost half a metre long too.
They can change their colours and body shape rapidly and are known as chameleons of the sea.