Elephant

The trunk is also used for drinking. Elephants suck water up into the trunk—up to 14 litres (15 quarts) at a time—and then blow it into their mouths. Elephants also suck up water to spray on their bodies during bathing. On top of this watery coating, the animals will then spray dirt and mud, which dries and acts as a protective sunscreen. When swimming, the trunk makes an excellent snorkel.
This appendage also plays a key role in many social interactions. Familiar elephants will greet each other by entwining their trunks, much like a handshake. They also use them while play-wrestling, caressing during courtship and mother-child interactions, and for dominance displays; a raised trunk can be a warning or threat, while a lowered trunk can be a sign of submission. Elephants can defend themselves very well by flailing their trunks at unwanted intruders or by grasping and flinging them.
An elephant also relies on its trunk for its highly developed sense of smell. By raising the trunk up in the air and swiveling it from side to side, like a periscope, it can determine the location of friends, enemies, and food sources.
Some elephants have been afflicted by floppy trunk syndrome.