Mob for the Dripstone Caves: Cave Crawler

This mob would be an aggressive mob. The mob would have 15 hearts or 30 damage points. It would have a rectangular shell made of a dripstone-looking material and it would have a square head and 6 spider-like legs. The tail would be almost as long as the shell. The head would have 2 sharp mandibles. The mob could break stone and dripstone blocks after about 5 seconds of digging if it was chasing the player. If the mob got close, it would grab you with it's mandibles and keep you trapped. The player would take 1 damage point every second until they damaged the mob about 10 damage points. It would be able to climb stalagmites because there are so many in that biome. I think this mob would spice up the dripstone caves and make it a bit more dangerous.