Pata-Bata
From Sonic Retro
Pata-Bata (パタバタ) is a badnik featured in Sonic CD. It is based on the butterfly.
They fly around in a zig-zag pattern, so be careful not to hit them on the way up from a spring, when Sonic is vulnerable. When broken down due to age, they fly slower and have a noticeable hole in their wings.
PC Manual Description
The Robot Butterfly flutters up and down through the air spying on enemies.