Hotaru
From Sonic Retro
Stardust Speedway Badnik 4, not listed in any Sonic CD manual, is a strange firefly badnik. It flies around for a short while, then gets situated on screen. It situates itself in such a way that no matter where or how you move, they don't. Then they light up and shoot a line of electrified balls out, then fly away, never to be seen again. Hit them before this happens!
A variant appears in [[Metallic Madness] Act 3, immediately before the boss. They shoot a laser straight down, then fly to a different part of the screen and repeat.