Diplodocus are passively tamed by feeding requested berries or kibble while avoiding their pushing attacks, with a safe position beneath the belly or against an obstacle helping you remain in place. They serve as speedy, high-capacity transport mounts that can carry supplies and multiple passengers, while their strong knockback disrupts enemies and provides defensive support despite minimal direct damage. When encountered, keep them away from cliffs, water, and bases, fight from beneath the belly, and beware that their knockback can endanger you or your tames. Once safely positioned, they are relatively defenseless and can provide meat and hide.