Elephants have these characteristics:

1. Long nose: Elephants belong to the order Proboscidea. They have a long, flexible and curlable nose with finger-like ends at the end of the nose. It can pick up small items.

2. Big ears: The main external features of the elephant are the flexible and muscular proboscis and the large fan ears, which have the function of winding and are powerful tools for self-defense and feeding.

3. Ivory: The upper two incisors develop into long and curved tusks. The tusks are important weapons for defense against enemies. The largest ivory recorded was 350 centimeters long and weighed about 107 kilograms.

4. Elephants are the largest terrestrial gregarious mammals in the world and usually move in family units. The elephant's cortex is very thick, but the skin between the cortex folds is very thin, so mud baths are often used to prevent mosquito bites. Ivory is an important weapon in defense against enemies.

5. The ancestors of elephants appeared on the earth tens of millions of years ago. The elephant family was once one of the most dominant animal groups on earth, and more than 400 species of fossils have been discovered.

Reference: Elephant (Mammalia) - Baidu Encyclopedia