The Marble Zone boss is the second boss in the original 16-bit version of Sonic the Hedgehog. The player faces him at the end of Marble Zone Act 3 and requires to be hit eight times. Here, it is piloted by Dr. Robotnik, who has equipped his mobile with a tube that drops fireballs from its underside.
The boss battle takes place on two stone grounds, on either side of a pool of lava. Dr. Robotnik will arrive from the right at start, who drops a fireball on each platform in turn, temporarily covering it in flames. The flame lines are divided into two directions, forcing Sonic to jump between them. Dr. Robotnik keeps doing this pattern until his mobile gets destroyed.
The player is able to defeat this boss by Spin Jumping into him when Dr. Robotnik starts arrive to shoot fireball on him. The player has then move away to the other side of lava pool and have to keep doing same strategy. After eight hits, the mobile will get damaged, but Dr. Robotnik will manage to escape. The player is then able to head to the capsule and head to the next zone. In the 2013 re-release of the game, the arena is much more extensive to that in the original game due the widescreen ratio on the re-release.
In other media
This Eggmobile configuration also appears in Archie Comics's Sonic the Hedgehog #226, that is part of GENESIS arc. and where it is piloted once by Dr. Eggman. When the doctor learned that Sonic had been foiling Snively's doings, he arrived in the Marble Zone to face Sonic himself in the Eggmobile that had a small hole for dropping fireballs.
When Dr. Eggman started chasing Sonic, who kept balancing on pillars in the lava lake, he eventually came to a dead end. There, Eggman almost got him when a Buzz Bomber, which had been reprogrammed by Rotor to help them, tried to attack him from behind. Though Eggman destroyed the Buzz Bomber, it gave Sonic the chance to attack the Eggmobile, causing it to get damaged by a pillar. Eggman then chose to escape, but blustered that once his master plan was being completed, all of them would suffer his wrath.
- This boss battle is referenced in the Metallic Madness Zone Act 2 boss in Sonic Mania. The Gashapandora dispenses a miniaturized version of the Marble Zone boss to fight a mini version of either Sonic, Tails or Knuckles.