The Eggmobile, also referred to as Eggman's Mobile, the Egg-O-Matic and occasionally the Eggpod, is the principal conveyance of Dr. Eggman. With its distinctive yellow and black hazard stripes adorning the sides, and an obsidian hemispherical underside suitable to carry the egg-shaped genius, Dr. Eggman has been piloting the machine since his introduction in the original Sega Mega Drive game Sonic the Hedgehog. Though built for the exclusive use of Dr. Eggman, there have been brief moments when someone else has been seen piloting the craft, most notably in the games Sonic the Hedgehog 3 and Sonic & Knuckles where Sonic the Hedgehog, Miles "Tails" Prower, Mecha Sonic, and an Eggrobo all get a turn inside the doctor's personal ship.
Though the base model is designed primarily for transportation, the Eggmobile is also compatible with a variety of attachments that Dr. Eggman has created in an attempt to foil Sonic the Hedgehog from putting an end to his latest plan. With each game, the Eggmobile has been slightly redesigned to coincide with Eggman's latest ideas. In the first game, the attachments were simple concepts that connected to the bottom of the ship, meant to swing or stab at the hedgehog. In Sonic the Hedgehog 2 these extensions of the pod grew more complicated, becoming almost the entire ship. However, with each defeat, the parts that were fastened to the craft would come exploding off, Dr. Eggman quickly vacating the premises. By Sonic the Hedgehog 3, simply adding elements to the Eggmobile for each battle had grown obsolete, the mobile redesigned to be a smaller craft so that it could easily dock in and out of whatever boss machine Eggman had come up with. This new design not only allowed far more complicated ways to try and stop Sonic, but also transformed the Eggmobile into a reliable escape pod, providing it the ability to quickly detach itself and flee to allow the pilot to live and fight another day.
Though variations on the end-level encounters have happened, more often than not the template set in the early games have remained. This set up was even poked fun at in the final Eggman-encounter in the game Sonic Unleashed when Sonic, at that moment trapped in his "Sonic the Werehog" form, tore apart the Egg Dragoon boss, ripping Dr. Eggman and his Eggmobile out of the machine and tossing it into the distance.
One common accessory the Eggmobile has had through its many interpretations is a claw of some kind on the bottom of the craft, with the ability to pick up and carry a variety of items. The most famous example of this would be from the Hidden Palace Zone encounter in Sonic & Knuckles, where Eggman snatched the Master Emerald from its sacred altar, electrocuting Knuckles the Echidna in the process (though only enough to stun him momentarily). The same claw would pick up Knuckles in his version of the Sky Sanctuary Zone. Most curious is the one occasion in which Dr. Eggman himself grabbed Sonic in the Under Ground Zone from the 8-bit version of Sonic the Hedgehog 2. Saving Sonic from certain death in an inescapable lava pit, instead the doctor carried Sonic over to the boss from that level, perhaps only hoping to defeat Sonic by his own hand, and unhappy if a natural force were to do the honors for him.
Also of note is that, while nearly every time the Eggmobile is shown it is floating on its own power, its first appearance in Sonic the Hedgehog 2 shows it descending into the Drill Eggman vehicle of the Emerald Hill Zone using a propeller, an item that does not return for the remainder of the game.
A Sega Dreamcast is hidden underneath Dr. Eggman's Eggmobile seat in Sonic Unleashed.