The Egg Libra (エッグライブラ Egguraibura?) is the boss of Night Carnival from Sonic Rush. It is the fourth boss for Sonic the Hedgehog and the first boss for Blaze the Cat. It is either controlled by Eggman Nega (if playing as Sonic) or Dr. Eggman (if playing as Blaze).
The Egg Libra is similar to a libra scale or a merry-go-round like-machine. One of the ball pits holds an Egg Mobile inside. Its color scheme different between the characters facing it:
- Sonic: Mostly gray, it has blue like-arms, pink and orange like-hands, and red and gray on one ball pit, while the other is red, blue, and white. The bots it drops are green.
- Blaze: Mostly gray with orange like-arms, lime green like-hands, and lime green and gray on one ball pit, while the other is red, blue, and white. The bots it drops are colored purple and pink.
The Egg Libra is a contraption resembling a scale, therefore one of the scales contains the electric ball, while the other scale is Eggman's/Eggman Nega's cockpit. Once the electric ball is discharged of its electricity the player can hit it, which will drop Dr. Eggman/Eggman Nega's pod down long enough for Sonic/Blaze to attack it. In addition, it also spawns a small robot decoy that crawls around a short section of the circular stage. If hit from above, this robot will launch the player upwards after it has been destroyed and the player can easily damage the cockpit if timed correctly. As the Egg Libra takes more hits, it will circle faster and the electric ball pit will have less time with no electricity. Once the cockpit has been hit six or eight times, the Egg Libra is defeated.
The nature of this boss fight differs from other bosses in that there are no attacks scripted to happen one after another. For example, the Egg Libra may sometimes use two of the following attacks at the same time.
- Electric attack: The electric ball that sits on the opposite end of Eggman's/Eggman Nega's cockpit will spin around continuously and try and zap the player with it. It will always shoot out four bolts of electricity that the player can avoid by jumping, or timing their movements to get out the way.
- Low sweep: Usually in the latter half of the fight, the spinning electric ball will tilt towards the floor, meaning the player must duck until it tilts back into its regular position. If there is a robot decoy around when the boss performs a low sweep, the player won't be able to use it to hit the cockpit, as it won't give them enough altitude to hit it.
- Ground slam: The Egg Libra will stop spinning briefly and slam its electric ball onto the floor, creating shockwaves in both directions. The player must jump over these. The speed these shockwaves occur is chosen randomly, either they will travel slowly, or very fast.
- The Egg Libra is named after the Libra constellation.
- Unlike the other bosses, the Egg Libra is the only boss in the game that does not require an opening or an attack for the player to strike at. Eggman's/Eggman Nega's cockpit is always vulnerable, meaning a skilled player can actually defeat it quite quickly.