March Hare is a Mad Hatter's best friend Alice in Wonderland.
March Hare first appears in the middle of the film having tea with Mad Hatter and the Doormouse. As they sing the Unbirthday song they are interrupted by Alice who commented she enjoys their singing pleasing the hare. The March Hare explains to Alice the purpose of an unbirthday and she joins for tea. March Hare continuously cuts Alice off as she tries to tell how she ended up in Wonderland. When the party is intruded again by the White Rabbit, Mad Hatter claims his watch is two days slow and with the March Hare's assistants fills it up with unnecessary things like jam. The watch then goes mad and the hare smashes it with a mallet and celebrates the White Rabbit's birthday by tossing him out the party. Later on, when the Queen of Hearts calls a trial upon Alice for the crime publicly embarrassing her majesty, the March Hare is one of the witnesses called forth to speak of the incident. However, when asked what he knows of the situation, he answers "Nothing!". Moments later, he and the Mad Hatter celebrate the Queen's Unbirthday after the King of Hearts mentions the day being such, distracting from the actual trail at hand. When the Cheshire Cat arrives at the party, though, the Dormouse goes into a panic, with the King trying to stop him with a mallet, accidentally whacking the Queen, instead. The Hatter and the Hare are able to escape her wrath, however.
Lastly, the Hare and Hatter are seen as Alice tries to escape the Queen and her card soldiers, insisting that she stay in Wonderland for a cup of tea, only to soon vanish as the girl's entire adventure was nothing more than a dream.
The March Hare (just like everyone else in Wonderland) is mad. The hare is best friends with the Mad Hatter and enjoys tea just as much as him. Although they are close and both insane, March Hare seems to be a bit more loud and wild than the Hatter who is a bit more gentleman like. Besides the Cheshire Cat, the March Hare seems to be the only one not to have a true fear of the Queen of Hearts being that he was capable of screaming in her face "Nothing Whatever!"