Place beer in your passive-taming slot, isolate the Deinotherium from its herd, and reset its behavior from a safe distance before approaching on foot. Wait until it completes the ear wiggle, trunk movement, and head shake, then walk beneath its head so it can take the beer; do not approach if its ears or trunk are pulled back. Be ready to flee immediately if it raises a foot, and use barriers or a mount while watching for the herd and nearby predators.