Stage 7 Sub Boss: Dr. Zero and the Claw
If you saved the General on Stage 6, Axel and company go on to stop Mr. X at his syndicate hideout. Before you fight Mr. X himself, you have to deal with this fool, Dr. Zero and his robotic claw~!. Yeah this sub boss is incredibly easy, the only real chance of damage would be to get shoked by the electric wall by mistake.
This was played on "Very Hard" mode.
GRAND UPPA~!