Doctor Robotnik’s Whirlpool Machine (ビッグシェイカー Biggusheikā?, lit. "Big Shaker"), is the second sub-boss in Sonic the Hedgehog 3. It is encountered in the first act of Hydrocity Zone and takes six hits to being destroyed. The mid-boss robot has round-shaped body with red-metallic skin and yellow lines formating X-formation on the central. The robot also is seen to have purple eyes. Its main weapons in the battle are thruster missiles, that protect him from the player's attacks, as they're spinning around the body until he plants himself on the cylinder to use his whirlpool attack.