A dwarf elephant is a small species of elephant. The streets of Old Volantis are overrun with white dwarf elephants which are used as a mode of transport. A single dwarf elephant pulls an ornate cart called a hathay, which is similar to a Westerosi oxcart but far more decorative. In Volantis persons of quality travel by palanquin, or in the back of the hathay. Thus far dwarf elephants have only been mentioned in Volantis.
The hide of the dwarf elephant is white in colour. The elephant that pulls Quentyn Martell's hathay is the colour of dirty snow. Tyrion Lannister espies a dwarf elephant whose hide is as white a bone. A dwarf elephant can emit a honking noise. The rump of the elephant makes as rolling motion as it walks.
A Dance with Dragons
While held captive by Ser Jorah Mormont in the common room of the Merchant's House, Tyrion Lannister thinks he glimpses Illyrio Mopatis for half a heartbeat, but it turns out to be a white dwarf elephant passing the front door.