Drill Eggman
From Sonic Retro
The first boss of Sonic the Hedgehog 2. Robotnik attacks with a small buggy with a drill attached. Players must simply jump on the cockpit eight times to defeat him. As a last ditch attack, Robotnik will fire the drill attachment before the boss is defeated.
This boss also appeared in Sonic Advance's X Zone. It had a reduced hit count and the original music.