The GPO aka the giant Pacific octopus is one of my favorite animals of all time. A close second would be the shark family. They are perfect in every way way and the only thing that could make them more formidable, is if they possessed the mind of an octopus.

A little bias but snakes without them we would be over run with rodents that carry disease and consume the food we produce.
beautiful colors and patterns.

They don't deserve the hate they receive.

"So long, and thanks for all the fish."

Since tardigrades have already been mentioned, it's apposite to point out that these organisms can survive a truly amazing range of conditions. Thus far, experiments have demonstrated that they can survive being desiccated for 30 years or more, temperatures in excess of boiling water or colder than liquid nitrogen, and have even survived being inserted into an electron microscope, subjected to a vacuum and irradiated with electrons from the microscope's electron gun. Two of the papers in my entomology collection cover an experiment in which tardigrades were exposed to the conditions of space in low Earth orbit, and even survived said exposure for 13 days.

Relevant papers covering tardigrades surviving in space include:

Tardigrades Survive Exposure To Space In Low Earth Orbit by K. Ingemar Jönsson, Elke Rabbow, Ralph O. Schill, Mats Harms-Ringdahl and Petra Rettberg, Current biology, 18(17): R729-R731 (9th September 2008)

Vacuum (imposing extreme dehydration) and solar/galactic cosmic radiation prevent survival of most organisms in space [1]. Only anhydrobiotic organisms, which have evolved adaptations to survive more or less complete desiccation, have a potential to survive space vacuum, and few organisms can stand the unfiltered solar radiation in space. Tardigrades, commonly known as water-bears, are among the most desiccation and radiation-tolerant animals and have been shown to survive extreme levels of ionizing radiation [2–4]. Here, we show that tardigrades are also able to survive space vacuum without loss in survival, and that some specimens even recovered after combined exposure to space vacuum and solar radiation. These results add the first animal to the exclusive and short list of organisms that have survived such exposure.

Extreme Stress tolerance In Tardigrades: Surviving Space Conditions In Low Earth Orbit by Dennis Persson, Kenneth A. Halberg, Aslak Jørgensen, Claudia Ricci, Nadja Møberg & Reinhardt M. Kristensen, Journal of Zoological Systematics & Evolutionary Research, 49 (Supplement 1): 90-97 (2011)

Most terrestrial tardigrade species possess the ability to enter a reversible ametabolic state termed anhydrobiosis in response to desiccation. In the anhydrobiotic state, tardigrades display an incredible capacity to tolerate extreme environmental stress, not necessarily encountered in their natural habitat. In this study, we determine the effect of different extreme stresses on initial survival, long-term survival and fecundity of selected species of limno-terrestrial tardigrades. The primary focus was to assess the effect of cosmic radiation. This was achieved through the RoTaRad (Rotifers, Tardigrades and Radiation) project on the BIOPAN 6 mission, funded by Agenzia Spaziale Italiana under the European Space Agency. To test their tolerance of space environment, tardigrades were sent into low earth orbit, and exposed to cosmic radiation and a microgravity environment. Experiments on Whatman-3 filters show an effect of cosmic radiation on the survival of the eutardigrade Richtersius coronifer just after returning to Earth; however, after 2 years of desiccation on Whatman-3 filters, none of the tardigrades previously exposed to cosmic radiation could be revived. In a microcosmos experiment, the tardigrades R. coronifer, Ramazzottius oberhauseri and Echiniscus testudo were desiccated on a moss substrate together with rotifers and nematodes. Very low survival rates were observed in this experiment, likely due to the applied desiccation protocol. Embryos of the tardigrade Milnesium tardigradum were also exposed to cosmic radiation; they all hatched in the laboratory after the flight. In addition, experiments testing extreme cold and vacuum tolerance in R. coronifer show that tardigrades in anhydrobiosis are unaffected by these conditions.

Mind you, there's an organism with even better radiation resistance than tardigrades, in the form of the bacterium Deinococcus radiodurans. This bacterium can survive a radiation dose of 5,000 Grays (the upper limit for tardigrades is 4,000 Gy). By contrast, 5 Gy is the lethal dose for humans.