What are long threadlike cells thta animals move their bodies?

The long threadlike cells which help animals move their bodies are called muscle cells. Muscle cells are types of cells found in muscle tissues. They are also known as muscle fiber or myocyte. They come in different specialized forms with various characteristics and properties. Each of the muscle fiber contains myofibrils or very long chains of contractile units of cell (sarcomeres).  It is the skeletal muscle fibers that help support and move the body of the animals and tend to have peripheral nuclei.