Amphibious. The bone crab can breathe air and water.

Bone Camouflage. The bone crab has advantage on Dexterity (Stealth) checks made to hide among bones.

Limited Telepathy. The bone crab can magically communicate simple ideas, emotions, and images telepathically with other bone crabs in its pack within 100 feet of it. While within 30 feet of another bone crab, the bone crab can't be surprised and has advantage on initiative rolls.

Pack Tactics. The bone crab has advantage on attack rolls against a creature if at least one of the crab's allies is within 5 feet of the creature and the ally isn't incapacitated.

Standing Leap. The bone crab's long jump is up to 20 feet and its high jump is up to 10 feet, with or without a running start.

White Ghost Shivers. A creature that eats the meat of the bone crab or that is bitten by a creature infected with the white ghost shivers disease must succeed on a DC 11 Constitution saving throw or become infected with the disease. An infected creature develops the first symptoms after 24 hours. Symptoms include a mild chill that escalates to a fever and frightful hallucinations that give the disease its name. At the end of each long rest, the infected creature must succeed on a DC 11 Constitution saving throw or suffer one level of exhaustion. The exhaustion lasts until the creature finishes a long rest after the disease is cured. A creature that succeeds on two saving throws against the disease recovers from it. Alternatively, the disease can be removed by the lesser restoration spell or similar magic.