The Feathertail Glider ( Acrobates pygmaeus ) , also known as the Pygmy Gliding Possum , Pygmy Glider , Pygmy Phalanger and Flying Mouse , is the world 's smallest gliding mammal , and is named for its long feather-shaped tail . The Feathertail Glider ( Acrobates pygmaeus ) , also known as the Pygmy Gliding Possum , Pygmy Glider , Pygmy Phalanger and Flying Mouse , is the world 's smallest gliding possum and is named for its long feather-shaped tail .