Here’s a nifty video (mpg) of an octopus confronting an ROV working off Vancouver Island. The poor thing was just trying to crush and eat an interloper (or perhaps disassemble it for spare parts to use in its high-tech scheme to take over the world), and the ROV operator uses its thrusters to fling debris at it and drive it away.
It’s quite a battle, and the octopus holds on for a surprisingly long time in the face of an extremely obnoxious machine.