Rhino scorpion - Like a lionfish, they can be venomous, Not deadly and obviously approach with caution of getting a sting that sticks around with pain for a few hours. Most scorpions lie on bottom and wait until their prey are within reach. They will then open their mouths and in a fraction of a second opening their gills. This creates suction which pulls their prey in. They will eat almost anything that will fit in their mouths and most will only take to live foods initially. Once acclimated and adjusted to their tank, with persistance they can be trained to accept frozen foods.
They do not have to eat everyday, twice or three times a week should be sufficient.