Totoro

Totoro is the title tetartagonist in Studio Ghibli's film My Neighbor Totoro, as well as its sequel, Mei and the Kittenbus. He is the mascot of Studio Ghibli.

Princess Mononoke
(Although this is a canonical information, it contradicts with the other canonical information) The survived Kodama seen at the last of the film later turned into Totoro.

Another Background Story
Totoro is a remnant member of Totoro Tribe which is at brink of extinction due to ancient battles against humanity.

Totoro learned how to create Jōmon pottery from humans in Jōmon period, and also learned how to spin a spinning top from humans in Edo period.

My Neighbor Totoro
Mei first encounters the small Totoro, followed by his medium companion, while running around the house's yard and spotting their acorns. She follows them into the forest where she discovers Totoro taking a nap. Although he is clearly surprised by her presence, he ultimately lets her fall asleep on his chest.

Later, he arrives at the same bus stop where Mei and Satsuki are waiting for their father. He wears a simple leaf to protect him from the rain: Satsuki gives him their father's umbrella. Totoro is intrigued by the sound of rain dripping from the trees landing on the umbrella, and even playfully jumps on the ground to cause more to fall. Eventually, the Catbus arrives to take him on his way. Before he leaves, he gives Mei a gift of acorns wrapped in bamboo leaf for the girls to plant.

Sometime later, he leads the other Totoros in a song and dance to make the acorns the girls planted grow. They are joined by Mei and Satsuki. He then invites them on a ride on his magical flying top, which they use to fly to the top of the trees and play his acorn flute.

When Mei gets lost trying to get to the hospital, Satsuki seeks out Totoro and asks for his help in rescuing her. Totoro gladly obliges, summoning the Catbus and sending Satuski off with it to find Mei.

He is last seen playing the flute while observing Mei and Satsuki's return home. Over the end credits he and the other Totoros harvest and feast on acorns, and during the winter discover a snow-Totoro (presumably made by Mei and Satsuki).

Mei and the Kittenbus
Mei meets Totoro again while he is joining several of his fellow forest spirits in a gathering for the Cat Liner. Although silent as ever, he is clearly excited to see Mei again, and he helps her introduce herself to the Cat Liner.

Appearance
Totoro appears as a large furry creature with grey fur and beige belly with grey arrows on his chest. He has pointy ears, long whiskers along with large paws with long claws. When he floats his mouth expands greatly. His silhouette vaguely resembles that of an owl.

Trivia

 * Totoro's name is delivered from Neighborhood troll in Tokorozawa.
 * His appearance is based on Horned owl, and his name during concept was Miminzuku, delivered from Mimizuku, Japanese name of Horned owl.
 * Totoro made an appearance in Kiki's room as a plush in Kiki's Delivery Service.
 * Totoro made a cameo appearance in Pom Poko, where he is seen flying on his top while holding Mr. Kusakabe's umbrella.
 * Small Totoro appears as a magnet on Lisa's fridge in Ponyo.
 * He also makes a cameo in Toy Story 3 as one of Bonnie's Toys.
 * Like the film name, his Chinese name counterpart is also 龍貓.
 * The Japanese book has a character introduction page, where it is named as Big Totoro and his friends are named middle and small Totoro. In the film he is always just called Totoro instead of "Big Totoro".