Cornelius is Babar's royal advisor, as well as his most trusted and loyal servant. He is kept throughout the series as one of Babar's closest friends, despite working for him domestically. He has close bonds with Pompadour, and frequently works alongside him while assisting Babar in his kingly duties. He is elderly, but is quite spry and possesses a great deal of wisdom. He is a bachelor and has no family that we know of. On several occasions, Cornelius has shown that he can be a powerful character, examples including but not limited to episodes like "The Coin" and "The Old Lady Vanishes". His personality changed into a form of intimidation, and he commands a large amount of respect in these episodes. He has saved Celesteville from terror a number of times, sometimes from natural causes and rarely even from Rataxes himself. Cornelius has also showed his ability to move the plot line of an episode along. In "A Child in the Snow", his knowledge of the Great White Mammoth introduced the true reason of the journey into the mountains. In "Conga the Terrible" his refusal to admit to his old age being the reason for the shipwreck, he goes out to seek Conga himself in order to restrain the group. And in "A Pair of Queens" he develops a quick and effective strategy to catch 'Queen' Christina before she arrives to the airport in order for Flora to apologize and make things better.
He is quite large, towering over most other elephants. He has an apparent disliking of Rataxes, and regularly experiences inconsistencies with him. His old age is sometimes made fun of by Pompadour, which form a sense of humor throughout the show. He has a catchphrase - "My Tusks" - which is usually used informally. He is shown to prefer practical concepts over diplomatic ones, resulting in arguments with Pompadour which in one episode got the better of him ("Friendly Agreement"). He is on good terms with Arthur and Zephir, though sometimes he can create a bad relationship with the two (especially in "Never Cry Alien"). When Babar was born, some of his ideas for a name included "Horacio" and "Archimedes". We can see by this that he is very fond of ancient civilizations and their cultures. He also speaks for the Old King and is very defensive of his reputation, especially after his death.