Egg Mobile-H

The Eggmobile is the first boss in the original 16-bit version of Sonic the Hedgehog. The player fights him at the Green Hill Zone Act 3, where it is piloted by Doctor Robotnik and equipped with a massive, checker-board pattern wrecking ball that hangs suspended from its underside by a chain, swinging back and forth. Only known strategy usually for the player has to hop on the two floating platforms on the battle arena and hit the Eggmobile eight times in order to defeat this boss.

For simple equipped add-on, this version of the Eggmobile is by far Robotnik's most famous machine in entire Sonic the Hedgehog series and has reappeared in many other games such as Sonic & Knuckles, Sonic Advance and Sonic the Hedgehog 4.

Sonic the Hedgehog (1991)
In the original Sonic the Hedgehog, the battle takes place at the end of the third Act of the Green Hill Zone on a flat piece of grass with two floating platforms above it. Robotnik will fly down the arena and drop the wrecking ball from the Eggmobile. After that, it starts move on linear back and forth pattern across the screen, while swinging the wrecking ball from side to side.

To defeat him, Sonic must leap onto one of the floating platforms and then Spin Jump onto Robotnik's Eggmobile eight times. The only thing the player has to look out is the wrecking ball itself, which swings towards the player on the platform, but the player is able to hide below the platform as well. After hitting eight times, it will destroy the Eggmobile, as well as the chain and wrecking ball itself. Robotnik will flee, allowing Sonic to open the capsule, thus freeing all animals inside of it and having complete the zone.

In the original and numerous re-releases of the game, the player is easily able to get extra hits when Robotnik is moving down to the arena and before releasing the wrecking ball. In Sonic the Hedgehog Genesis, the player can do multiple hits by jumping and moving forward the Eggmobile. In 2013 re-release of original Sonic the Hedgehog, battle arena has been extended to fit widescreen ratio of the re-release, while also the moving pattern of Eggmobile with it's wrecking ball is slightly increased to move to another side at the time.

Sonic & Knuckles
The wrecking ball Eggmobile later makes an appearance as a mid-boss (despite having normal boss BGM playing) at Sonic's story of Sky Sanctuary Zone in Sonic & Knuckles. It takes place on a similar arena with two platforms at the 1/3 point of the zone. Unlike in previous times, the Eggmobile is this time piloted by Mecha Sonic, who flies down from the sky and releases the wrecking ball to swing it around.

The battle is mostly is similar like in original Sonic the Hedgehog, however the pattern of the Eggmobile is slightly different. When Mecha Sonic arrives to the other side of the arena, he makes makes the Eggmobile stop and then lets the wrecking ball swing to a very high height until it falls down the similar way and Mecha Sonic changes the direction. The player has to hit the Eggmobile eight times while watching out for the wrecking ball's swinging. Like in the original Sonic the Hedgehog, the player can do extra hits before Mecha Sonic flies down to the battle arena. After eight hits, the chain and wrecking ball gets destroyed and Mecha Sonic escapes with the exploding Eggmobile. The Warp Point will appear below the ground and can make the player progress to the higher levels of Sky Sanctuary Zone.

Sonic Advance
The wrecking ball Eggmobile appears in Sonic Advance, now known as the Eggmobile Hammer Ball (エッグモービル・ハンマーボール). It is the first boss of X-Zone. Once again it is this time piloted by Eggman with Eggmobile, that appearance has been taken directly from original Sonic the Hedgehog. At the beginning and after running over crumbling bridge, the player comes to the arena with two platforms, and the GBA variation of the boss theme from original Sonic the Hedgehog starts playing at the background. Eggman will fly down to the arena and then release the wrecking ball.

The battle against the Eggmobile Hammer Ball is slightly similar, even mostly easier than the original boss fight due having less than four hits to defeat it. However playing with Amy Rose, the player has to do Hammer Jump technique with Piko Piko Hammer into Eggmobile in order to damage it. Also the player now is unable to extra hits, when the Eggmobile flies down the battle arena. After four hits, the chain and wrecking ball once again gets destroyed while Eggman flies away with Eggmobile.

Sonic the Hedgehog 4
The wrecking ball Eggmobile is the first boss of Sonic the Hedgehog 4: Episode I. It is piloted once again by Doctor Eggman in the third, boss act of Splash Hill Zone. Normally the battle takes place on similar wide arena with two platforms, where Eggman flies down with his Eggmobile and releases the wrecking ball from the mobile. It then starts do normal swinging pattern back and forth. The player can easily hit the Eggmobile from one of two platforms, while watching for the swinging wrecking ball.

Upon taking five hits of damage, Eggman will retract the ball and flip 360 degrees, slamming it down where Sonic is. However, this also leaves him vulnerable as he retracts the wrecking ball again, preparing for another attack. Doing another four hits makes the wrecking ball and chain explode and Eggman slowly escapes once again with his Eggmobile.

The vehicle later appears again in E.G.G. Station Zone, that is boss rush before the final boss. The only difference in that zone is that platforms move up and down pattern, which can make little challenging. It also takes one hit to change its pattern to flip the wrecking ball 360 degrees. After doing four hits into Eggmobile, the player moves on to the next boss of the zone.

Adventures of Sonic the Hedgehog
In the unaired pilot episode of Adventures of Sonic the Hedgehog, Doctor Robotnik starts chasing Sonic on the zone that heavily resemblances Hill Top Zone. Robotnik also this time got the wrecking ball (which is colored black and white) with chain add-on on his Eggmobile, which he tries to swing toward Sonic during the chase. However Sonic easily dodges the wrecking ball and soon after takes it and gives it Robotnik to his hands. Sonic then tapes the whole Eggmobile along Robotnik and the wrecking ball, who then crashes to the tall mountain, thus completely destroying the Eggmobile with the wrecking ball add-on.

Sonic the Comic
The wrecking ball Eggmobile also appeared in an early issue of Sonic the Comic. Doctor Robotnik piloted the wrecking ball Eggmobile after brainwashing Tails and turning him into the cyborg Robofox. Robotnik nearly defeated Sonic the Hedgehog, who had been caught unawares by Robofox, until Tails broke through the brainwashing and destroyed the Eggmobile with a powerful Spin Attack.

A group of badniks in the Marble Zone later had one of the checker-pattern wrecking balls (which they referred to merely as "one of [their] Master's weights"), which they threatened to use to crush the squirrel Tufftee.

Sonic the Hedgehog (Archie Comics)
In the Sonic the Hedgehog comic series, the wrecking ball makes an appearance (under the moniker of "checker-wrecker ball") in the first story of the original miniseries as one of the machines Dr. Robotnik uses in attempt to defeat Sonic the Hedgehog. It backfires however, when Sonic uses a Power Ring to defeat Robotnik, causing the wrecking ball to crush his Egg-O-Matic.

It is later used by Snively in the Genesis arc, after the world is reset by Eggman, but Sonic quickly disposes of it.