Moosh is a character that appears in Oracle of Seasons and Oracle of Ages. He is a blue bear with the power of flight; this ability allows Link to be able to fly over pits while riding him. However, Moosh cannot fly forever and eventually needs to lands; he also cannot fly over water since he is afraid of it.  He also has a ground smash attack.
Oracle of Seasons
Moosh can be found while Link is exploring Mt. Cucco. Moosh asks Link to get the Spring Bananas that are atop of Mt. Cucco for him. After Link does this, Moosh helps Link on his quest to find the key to the Dancing Dragon Dungeon.
If Link has purchased a Strange Flute from the shop after the second dungeon, Moosh joins him at Spool Swamp after Link saves him from Moblins. Moosh turns the Strange Flute into Moosh's Flute.
Oracle of Ages
Moosh is the first of three Animal Companions who Link must help along his journey. Link first meets Moosh in the Yoll Graveyard while going to retrieve the Cheval Rope and Flippers from Cheval's Tomb. After being saved from a group of Octoroks, Moosh helps Link to fly over the holes leading to Cheval's Tomb. When the Flippers and Cheval Rope are obtained, Moosh leaves.
Moosh has the ability to fly over a longer string of area than Link can simply jump over, which becomes especially useful when having to cross a path filled with holes in the ground. As an attack, he can also use the Ground Pound technique, where he charges power while hovering over an enemy (or group of enemies), then release it by powerfully crashing to the ground. One downside to Moosh is that he cannot swim and sinks into any deep water that Link takes him in.
If Link does not gather a Strange Flute anywhere else throughout his adventure before entering the Nuun Highlands, then he encounters Moosh for a second time in the Fairies' Woods. There, the Fairies inform Link that Moosh has gotten lost within the Woods and needs help finding his way out. After helping Moosh for a second time, he gives Link his Moosh's Flute, which allows him to be called upon almost anywhere in the overworld and as frequently as needed.