Ender crab mob

Regular crab mob was shown in mob vote, and despite it being added would be still great and its claw it would drop could do what was told in mob vote presentation, it could be added alongside its ender counterpart
Ender crab should be hostile or neutral mob, located only in the end dimension on outer islands
It would attack player by regular leaping similar to how spider does, but could also latch onto back of players, slowly draining health, any damage caused to player or crab, during this, from any other source would make crab let go, this would include potion splash effect, fall damage, enderman, players with crab attached on them couldnt hit crab directly with melee weapons, for balancing, crab should probably also let go after some maximum duration of time, this would give unique threat and solution to it, multiplayer cooperation or usage of thorns (often detrimental and disregarded) enchantment would be in place or getting bit more creative with terrain and fall damage, when letting go, crab would be "stunned" for while so it would be easier to deal damage
Its drop would be Ender crab claw, which could let you pick up any block, holding it "stored" in claw (cant mine and use blocks for crafting by it) and placing them elsewhere instantly, would help builders correct mistakes in builds, wouldnt be able to move trial vaults, any spawners, portal blocks, bedrock and similar blocks not meant to be moved, itself would take some material in order to do it or lose durability