Mrs. Crab is a giant female alien crab that lived underwater on planet Namek and the mother to many baby crabs.
When the four star Namekian Dragon Ball into the ocean, the ball fell onto her back into the pile of all her Eggs. Bulma who was chasing after it in a Submarine attempted to go after the ball, but Mrs. Crab started attacking her and crushed her submarine making her escape in a robot suit. As Mrs. Crab tries to attack Bulma's suit, she dodges it. After her babies start to hatch from her eggs, a rock starts to fall over almost squishing the babies but Bulma decides to help the babies prevent it from falling on them and escape with the Dragon Ball afterwards.
She later pays Bulma back by helping her take out Blueberry and Raspberry who Bulma lead down to her by tricking them into thinking that her eggs were a giant pile of Dragon Balls. Although Blueberry and Raspberry manage to make it back out of the water and chase after Bulma, Mrs. Crab rises up to the surface and grabs both of them with her claws and drags them back into the ocean where they are never seen again.
She and her babies died off screen when planet Namek blew up from the battle with Frieza.
- The name "Mrs. Crab" was a nickname given by Bulma.
- Based on her antagonistic actions to Bulma, and later to Blueberry and Raspberry when they were in close proximity to her eggs (and in the case of the latter, trying to steal them), Mrs. Crab was extremely protective of her eggs and offspring.