We have all heard about how smart octopuses are. They are among the most intelligent of all invertebrates. The exact extent of their intelligence and learning capability is much debated. Some people even try to keep them as pets, but it is difficult, since they can escape out of “secure” tanks due to their problem-solving skills.
Here is a video of an octopus getting off the deck of a ship through a very unlikely opening. I thought this was amazing to watch.