Void Jaunt. As a bonus action, the crab can magically shift from the Material Plane to the Void, or vice versa while within 1 mile of a void rift.

Spider Climb. The crab can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Pincer. Melee Weapon Attack: +4 to hit, reach 10 ft., one target. Hit: 11 (2d6 + 2) bludgeoning damage. The target is grappled (escape DC 14) if it is a medium or smaller creature and the crab doesn't have two other creatures grappled.