Finding one is the real challenge, they are a rare spawn and furthermore get killed quickly by predators thanks to their slow speed and shared spawn zones with wolves and boars.

Once located, use a strong agile mount like an Allo or Carno to quickly kill every predator around it to stop them from killing your rare tame, then simply walk up to it and feed it a veggie cake.

Better yet just use an eagle to carry them somewhere safe.