Wiggler Fly
Flutters (also called Wiggler Flies) are Wigglers with wings, that first appeared in Super Mario World 2: Yoshi's Island. When hit they turn red and angry like normal Wigglers. Instead of flying around aimlessly though, they charge strait for the Yoshi that hit it.
Super Mario World 2: Yoshi's Island
In this game the Wiggler Flies are only in one level, "Go, Go, Mario!". Just before the goal and swarm of them appear over a flat turf. Avoid them by simply running under them.
In the remake, Super Mario Advance 3: Yoshi's Island, they appear again, in the secret level "Endless World of Yoshis".
Mario Party Series
In this game they are called Flutters. They are used as capsules in Mario Party 5 and Mario Party 6 to steal coins from a player. They also appear in some Mini-games. A Wiggler Fly named Flutter also appears Mario Party Advance. Two of the games quests directly involve it. It also appeared in Mario Party 7 as the Flutter Orb which could take players to the Star. She also appeared in the minigame Spider Stomp, where she was at the end of the level, and had to be rescued.
Mario Power Tennis
In Mario Power Tennis, for a defense shot Wiggler transforms into a Wiggler Fly.