Looking for a rock pool?

Looking for a rock pool?

Observation - Looking for a rock pool? - Southern Africa. Description: Looks asif it belongs in the sea babies are reminiscent of sea urchines, shell is covered in simil

Looks asif it belongs in the sea
babies are reminiscent of sea urchines, "shell" is covered in similar hard spines (looks and feel like a rash of raised, hard pimples)
skin is rough and tough - feels like cartilage