Eggwalker

The Eggwalker (エッグウォーカー Eggu Uōkā?) was a vehicle used by Dr. Eggman as his primary transportation in Sonic Adventure 2. It resembles Eggman's Egg Mobile with two legs added.

Description
It is armed with a Volkan Cannon that can shoot regular ammo, a missile launcher, lock-on capabilities, and punching glove. Upon finding certain items, the standard Volkan Cannon becomes a Bazooka, capable of destroying steel crates, the standard lock-on missile becomes a Laser Blaster, capable of "splash damage," and a Jet Engine, giving it the ability to hover in mid-air. The Eggwalker can also have its defenses boosted by finding the Protective Armor, something that the Cyclone does not have. The player uses the Eggwalker when playing as Eggman and fights against the Cyclone twice and when playing as Tails, who uses the Cyclone in the same manner as Eggman.

In 2 Player Mode and the second battle for Tails, it's also equipped with a rocket launcher and a laser cannon. In the Dreamcast version, Big the Cat can use the Eggwalker in 2 Player Mode in place of Eggman.

Archie Comics
The Eggwalker makes an appearance in the Sonic the Hedgehog comic book series and its spin-offs published by Archie Comics. When Dr. Eggman decided that he would personally take out the G.U.N. Aircraft carrier, he used his wrecked Eggmobile in order to build an Eggwalker with two side seats for Orbot and Cubot. After destroying many of the G.U.N. forces on the carrier, Eggman escaped and had his Eggwalker detonate, sinking the craft.

Eggman further refrences Sonic Adventure 2 while he is escaping, stating "Now you know why I am the best!", which is what he would say after getting an A-rank.