His role in the Kingdom Hearts series is to royally introduce his queen, blowing his trumpet to signal the beginning of the usual Wonderland trials.
The White Rabbit is very unorganized and usually seen in distress. As a result, he is often late when it comes to fulfilling his duties and talks to himself aloud as he struggles to get to his destination on time. Although he is quite a nervous and unorganized character, he is very loyal to his Queen. This could easily be out of fear at the thought of making her upset which would cause him to lose his head.
Although the White Rabbit seems to be of a good nature; he is a neutral character. He is likely to go through with bad deeds if the Queen of Hearts wishes him to do so.
The White Rabbit is a small and elderly rabbit with a large red nose and short ears. He is seen wearing spectacles, grey pants with a hole in the back for his tail, and a red over-coat and bow tie which is worn over an orange button-up shirt with a white collar.
However, he does not wear any shoes. He always carries his large golden pocket watch with him. When starting the Queen of Hearts' trials, he usually blows his golden trumpet, which is small and easily held in one hand.
Sora, Donald, and Goofy first come across the White Rabbit in the Rabbit Hole, shortly after landing in Wonderland. He runs through the area in a panic; late to introduce the Queen of Hearts and to begin Alice's trial. The trio follow the White Rabbit into the Bizarre Room, where they notice that he has somehow gotten smaller, and are left in confusion as the White Rabbit exits through a tiny door.
The Doorknob of the small door suggests drinking a bottle on the table. This causes the trio to shrink down, allowing them to enter the Queen's Court. There, the White Rabbit introduces the Queen, blowing his trumpet and signaling the start of the trial in which Alice is accused of attempting to steal the Queen's heart.
The White Rabbit's role in Kingdom Hearts: Chain of Memories is quite similar to his role in Kingdom Hearts, with some minor changes. When they first enter Wonderland, Sora, Donald, and Goofy are passed by the White Rabbit in the Lotus Forest, once again late to begin Alice's trial. The trio follow him into the Queen's Court, where he blows his trumpet so that the trial may begin.
This time, Alice is accused of being responsible for the Heartless and for stealing the Queen of Hearts's memory. The White Rabbit explains to Alice that the charges are very serious and without the Queen's memory they would not be able to get rid of the Heartless that are infesting the kingdom.
When Roxas goes on his first mission to Wonderland, he arrives in the Rabbit Hole just in time to see the White Rabbit run by. Once again, the White Rabbit is late and panics as he runs into the Bizarre Room. Similar to the events that take place in Kingdom Hearts, Roxas enters the Bizarre Room surprised to see that the White Rabbit has shrunken. The Doorknob explains that the blue bottle on the table will make Roxas smaller, so he uses it to shrink down in order to fight Heartless and complete his mission. As he leaves, he wonders to himself where exactly the White Rabbit had gone.
Later, Roxas is paired up with Luxord on a mission to eliminate some Pink Concertos. Although Roxas doesn't encounter the White Rabbit on this visit, he explains the encounter to Luxord before the mission begins.
When Luxord and Roxas return once more on a mission to locate and destroy three Commanders, the White Rabbit passes them in the Rabbit Hole, and Luxord convinces Roxas to follow. The two Nobodies follow the White Rabbit to the Queen's Court, and overhear him reporting to the Queen of Hearts.
The Queen's soldiers had been searching for a trio that had startled her and he explains that the only place they could be is the royal Rose Garden. The "trio" happens to be the three Commanders that Roxas and Luxord were sent to destroy. The White Rabbit's hint helps them to do so, allowing them to complete their mission.
Answering Alice's questions will reveal that she had been chasing the White Rabbit and that was how she fell down the hole.
In castle Oblivion, the White Rabbit drops his pocket watch. Sora has the option to either pick it up, or tell him that he dropped it.
In the film, the White Rabbit is the main reason why Alice enters Wonderland. He ends up being followed by her all the way to the Queen of Hearts various events taking place along the way. He is shown in the film as being a worrywart and being panicky and often being the victim of such people as the Dodo and the Mad Hatter.
In Alice's Adventures in Wonderland, the white rabbit's name is Herald.