The largest crab in the world is the killer crab, also known as the spider crab. The largest known record is the body of more than three meters long, because they are very large on average, so they are often falsely rumored to kill people, but those are just rumors, so far there have been no cases of killing crabs and injuring people, but people are used to taking care of their names, so they have been calling them crabs.

Killer crabs are exotic creatures that live in the waters off the southeast coast of Japan. This crab, called the Gan's giant crab, is a large spider crab that lives on the bottom of the northwest Pacific Ocean and is the largest known crustacean in the world, and has received a common English name for "Dead Man Crab" [1] due to its scavenging, which led china to translate it as a ghoul crab.
The prototype of the killer crab is the spider crab family, the giant crab of the spider crab genus, also known as the Japanese spider crab or tall crab, because of its resemblance to a tall spider. Giant crab is the only remaining species in this genus, which is mainly distributed in the waters around Japan, and has also been sporadically reported in the East China Sea. This crab is really big. However this is mainly the length of the legs and its torso is not large.
The length of the giant crabs collected by fishermen is about 1.0 to 1.2 meters. While giant crabs are indeed meat-eating creatures, the scene of killing people on the coast and eating them separately on the coast is too exaggerated. And they mainly live in deep water of 50 meters to 600 meters, and even if they wander to the shore, they should only be scattered soldiers.
Killer crabs live in Iwate Prefecture, Japan, beyond the northeastern corner of Taiwan, in the Pacific Ocean, at depths of 500 to 1,000 meters, with an average temperature of 10 to 15 degrees Celsius, and feed on sharks, hagfish, crabs and various fish. Crossing the group life and hooking up opponents with the claw determines the status. The leader has the right to rest on the stone, and the advantage of looking down on the flock of crabs.
The largest surviving spider crab in the world is the Gan's giant crab that lives in the waters of Japan, and they are also the largest of the surviving arthropods. They have long claws, the largest of which is 4.2 meters long, 38 centimeters long, weighs 20 kilograms and has a lifespan of 100 years. Found in the North Pacific in Japan. Even such terrible-looking crabs are caught and fed by humans, and they are big enough for a family to eat.
The largest killer crab found so far in the UK is said to have a body about the size of a blue ball, and the two claws spread out at 3.5 meters, almost a half-length of Yao Ming. There are rumors that these giant killer crabs have been mutated and aggressive due to the radiation of various nuclear wastes in the sea, but this claim has not been confirmed.