Scientists have spotted octopi carting coconut halves around and using them to hide in, or to protect themselves from predators:
You may think this is cute and all, but think about it: they’re building tanks. This is prototype armor for the oceanic invasion. When Mother Earth gets sick of us screwing with her, her aquatic minions will come fully armored for battle.
When the sharks and giant squid figure out armor, we’re hosed.