Batbot
From Sonic Retro
The Bat-Bot (called Halogen in the Japanese Manual) badnik is a bat-esque badnik found in Carnival Night Zone. They fly towards the player in circular patterns. Avoid touching their lightbulb, and destroy them from above. This robot then served as inspiration for the Slot enemy.
Inspiration for this badnik could've come from the un-named bat badnik in Sonic 2 Beta's Hidden Palace Zone- both share a similar behaviour.