Egg Bomber Tank
From Sonic Retro
The Egg Bomber Tank is the second boss of Sonic Advance 2, appearing in Hot Crater. In this boss, you must avoid the cannonballs that Eggman fires, hit the barrel 8 times, and then you can attack the cockpit. However, Eggman will still drop cannonballs, but since they roll low this time, they're easier to avoid. Hit him 4 other times to defeat the boss.