A biological pigment that gives color to skin, hair, and eyes in animals, and also absorbs Ultraviolet light to protect underlying tissue.
A giraffe's tongue reaches 45–53 cm with a tip colored deep blue, black, or purple. The dark hue comes from melanin, and the leading explanation is ultraviolet protection: giraffes spend 16–20 hours browsing with the tongue out, so its most exposed part needs sunscreen.