I'm a little fuzzy on the methodology, but scientists think the Colossal Squid (Mesonychoteuthis hamiltoni) is more like Leatherface of "The Texas Chainsaw Massacre" than Freddy Kreuger of "Nightmare on Elm Street." It lies back and lets prey come to it (and doesn't eat so much) rather than stalking food sources.
Or so say these researchers.
BBC characterizes how they arrived at their conclusions about a cephalopod that's rarely seen by us humans:
(T)he team used a set of routine metabolic rates for other deep-sea squid species and extrapolated the data to match the colossal squid's size.They also factored into their calculations the cold temperature of the Southern Ocean the squid inhabits.
It's slow, too:
"Our findings demonstrate that the colossal squid has a daily energy consumption 300-fold to 600-fold lower than those of other similar-sized top predators of the Southern Ocean, such as baleen and toothed whales," says (Dr. Rui Rosa from the University of Lisbon in Portugal, who undertook the study with Dr. Brad Seibel from the University of Rhode Island, Kingston, US.)