The Sky Base Zone boss is the fifth and final boss of the 8-bit versions of Sonic the Hedgehog, fought at the end of Sky Base Zone.
Sky Base Zone's fight takes place in some sort of lightning chamber within the bowels of Dr. Eggman's airship. The fat man observes proceedings from inside a glass case, while Sonic must dodge hazards that vary by game version as well as the occasional energy sphere which the bad Doctor fires in the hedgehog's direction. The player should simply dodge the attacks and wallop Eggman's position with the right timing.
In the Master System version of the game, Eggman's main weapon is a scrolling pillar of electricity that periodically activates as it moves back and forth, and the player must strike when it deactivates. After a moderate amount of damage has been dealt, the timing of the lightning discharges becomes more erratic, putting more pressure on the player. In the Game Gear version, Eggman utilises three flamethrowers embedded in the floor instead, and the pattern does not change when he is close to defeat.
Once Eggman's case is cracked open after twelve hits, Sonic chases him to the end of the level. The obese scientist escapes via a teleporter to Green Hill Zone, but Sonic follows and clocks Eggman as he flies away in the Egg Mobile. The ending scene then rolls, where Sonic's Chaos Emeralds cleanse the taint of smog and pollution from South Island's summit should he have collected all of them.