Search youtube for Batman and the Exploding Shark... and enjoy!
That was a shot from the “Batman” feature film they did off the TV series back in the 60’s. Batman reaches into his Utility Belt and pulls out a can of “Bat-Shark Repellent” and sprays it on the shark.
In reality, octupi eat sharks. I saw a Nat Geo special on octupi once. An aquarium put small sharks in a tank with a octopus in it. After a day, they’d find a dead shark. They kept adding sharks, and they kept ending up dead...and they hadn’t a clue as to why. No other species was in the tank that would attack sharks...or so they thought. So, they rigged a video camera and added another shark. The next day, they found a dead shark, then reviewed the tape. Sure enough, they saw the octopus attack, kill, and partially eat the shark. They had no idea octopi were even capable of that behavior.