Ossicones: Giraffe and Okapi have these.
The two knobs on a giraffe’s head are NOT called ‘horns‘ or ‘antlers‘, they are called OSSICONES. These permanent structures created from ossified cartilage and covered with skin can also be found with the male okapi.
The difference between ossicones and antlers or horns: antlers area non-permanent bony structures and are generally shed and regrown annually; horms are permanent bony structures covered with keratin that continue to grow during the animal’s lifetime.