Tingle is a character from the Legend of Zelda series. He is a pudgy 35 year-old who describes himself as "the very reincarnation of a fairy." First appearing in Majora's Mask, Tingle has become a widely recognized, albeit despised character. He also has two known brothers named Ankle and Knuckle and an un-related man, David Jr.
In his first appearance in Majora's Mask, Tingle would sell maps to Link. He floats in the air with a red balloon and has to be shot down with a ranged attack before you can talk to him. In every area where he can be found he sells maps of that area and somewhere else. It is significantly cheaper to buy a map in the area it shows. Showing a photo of Tingle to his father, the swamp tour guide, will net you a piece of heart.
Oracle of Ages
In Oracle of Ages, Tingle appears in the land of Labrynna in the Forest of Time. When you reach him, he will provide you with the Island Chart (needed to cross the sea). He will also upgrade your Seed Satchel.
Tingle does not appear in the companion title, Oracle of Seasons, but you can receive the "Tingle Secret", which allows for another Seed Satchel upgrade.
The Wind Waker
In The Wind Waker, Tingle is in prison on Windfall Island because he has stolen a Picto Box. After rescuing him, he will thank you by giving you the Tingle Tuner and tell you that if you ever need help deciphering a map to visit him at Tingle Island. Late in the game when you find the Triforce Charts, Tingle will translate them for you, but for a hefty fee.
The Tingle Tuner lets you connect a Game Boy Advance to your Gamecube to get a map on your GBA and various abilities that cost rupees to activate. Additionally, you can use it to find hidden statues for his Island, his brother Knuckle, and pieces to a story that retells the story of Majora's Mask, but through Tingle's eyes.
Four Swords Adventures
In a much more minor role, Tingle appears in Four Swords Adventures' single player story, "Hyrulean Adventure". Tingle occasionally shows up trying to steal Force Gems for himself, which you can prevent by attacking him. He also has signposts throughout Hyrule labeled "Tingle Times" giving hints and stories of what's ahead.
You can also visit Tingle's Tower, which acts as a hub for multiplayer minigames.
The Minish Cap
In an even smaller role, Tingle (as well as his brothers) fuse Kinstones with the player and will inform them of how many fusions they still have to do throughout the game. Once you have completed them all, Tingle will reward you with the "Tingle Trophy", replacing the Kinstone Bag.