Balloon

Balloon was a magical bird from Romance Dawn V.2 and a friend to Ann. He was sought after by Spiel the Hexagon for his magical blood and was last of his species. He always returns to Ann's side no matter where she is when seperated.

Trivia
In One Piece, there is a scene where Luffy accidentally gets grabbed by a giant bird. The way the bird grabbed Luffy is similar to the way Balloon transported Luffy back to Ann. The title page of the manga chapter in which this scene happens also shows several small "Balloon" like birds.