Meat tenderizer, also known as a meat mallet or meat pounder.

The object shown in the image is a meat tenderizer. This kitchen tool, also known as a meat mallet or pounder, is used to tenderize and flatten cuts of meat. It typically has a handle and a heavy head with two different surfaces: one flat and one with spikes or teeth. The spiked side is used to break down the muscle fibers in the meat, while the flat side is used to pound and flatten it. This process helps to make the meat more tender and to ensure it cooks more evenly.