The Crab Statue is useless except for creating the Crab Engine, which has a 50% speed increase compared to 1 Second Timers. The Crabs spawned will not drop anything which makes it useless for anything else besides crab engines.
They have a 50% speed increase to 1 Second Timers. They are created with about 20-30 solid blocks, 1 pressure plate, 1 crab statue, and one switch. It should be set up like this. Guide by Yrimir(sub to him he's awesome)Crab Engine By Yrimir. They are the most efficient way to farm any item from statues. i.e hooking it up to goldfish statues, skeleton statues, piranha statues, or slime statues and having them die and drop stuff to be sold.