Technosqueek
From Sonic Retro
The Technosqueek (called Chu-chu in the Japanese Manual) is a rodent-like badnik found in Flying Battery Zone. They are found scuttering in ceilings, walls and floors. Jump on them to destroy them. "Chu-chu" is Japanese for squeak.
Since Sonic 3 and Sonic & Knuckles were one single game split in half, the Technosqueek was listed by accident in the Sonic 3 manual's badnik section.
