Balance Master, known as Mecha Ashika (メカアシカ) in Japan, is the third boss of the 8-bit versions of Sonic the Hedgehog 2, fought at the end of Aqua Lake Zone.
Balance Master is notable for requiring a more indirect attack strategy than most of the game's bosses. When it first confronts Sonic, Balance Master will promptly blow an explosive balloon on its nose; the balloon will pop before the boss can throw it at Sonic, damaging it and giving the player a clue on how to defeat the robotic pinneped.
The Mecha Ashika's main tactic is slowly shuffling towards Sonic, leaping towards him with a tail slap when it gets close enough; if Sonic tries to jump on the boss, it will catch him and bounce him for a few seconds before throwing him across the screen. After this, the seal will again try to inflate its explosive balloons; Sonic must attack these when they are almost inflated, popping them and damaging the boss (failure to attack the balloon will cause the boss to use it as a projectile). Repeating this five more times causes the robot to explode, allowing Sonic to proceed to Green Hills Zone.