Subsequent to the coronation of the Fire Lord Zuko, he started to find his mother, with the help of the Team Avatar and his unstable sister, Azula. They entered the Haunted forest, and there, Aang detected something using his Avatar power. His face showed some strange facial emotions that were typically similar with the gruesome face Aang made during their first meet with the Wolf spirit. Sokka spotted some marks throughout the forest that were making some faces. He appointed a knot of squirrel toads, a tree, and also a flutter-bat that was hanging around the Team Avatar. The bat flew away, but Aang chased and called it "Mr. Flutter-Bat". The flutter-bat, however, brought Aang to the Wolf spirit.
The flutter-bat is a mixture of bat with butterfly, as the name suggests. It has the body of a bat, and a head and the head of butterfly, with a light yellow proboscis. Its eyes were big and two eye marks stretched on its wings. However, unlike the real-world bat, it has no fingers at the end of its wings. It has no antennae, but two indigo ears replace the antennae.
The flutter-bat is a hybrid of bat and butterfly, as seems in the name. Bats are the only flying mammal in the real-world, and it could be seen only in the nighttime. They live in a cave, and always dangling reversed. Butterflies are day-flying insect that stays near flowers and herbs. They are important as pollinators for some species of plants although in general they do not carry as much pollen load as bees.