I believe the answer is a earthworm
Cardiac Muscle Tissue<span>. Cardiac </span>muscle tissue<span> is an extremely specialized form of </span>muscle tissue<span> that has evolved to pump blood throughout the body. In fact, cardiac </span>muscle<span> is only found in the</span>heart<span> and makes </span>up<span> the bulk of the </span>heart's<span> mass.</span>