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Sonic News Network
Sonic News Network

The Egg Poison[1] (ウォーターエッグマン[2] U~ōtā Egguman?, lit. "Water Eggman") is an object that appears in the Sonic the Hedgehog series. It is a modification of Eggman's Mobile created by Dr. Robotnik, who used it during the West Side Island incident.



The Egg Poison looks almost identical to the standard form of Eggman's Mobile, except that it has a tube-like crane that releases Mega Mack. It is as well mostly gray in color, and has black and yellow hazard stripes.

Features and abilities

The Egg Poison is capable of flight, and can fill its tube with Mega Mack, which it can then drop on its target.


Sonic the Hedgehog 2

In Sonic the Hedgehog 2, the Egg Poison was used by Dr. Robotnik to fight Sonic and Tails in Chemical Plant Zone. However, the Egg Poison was destroyed by the duo, forcing Robotnik to flee.

Other game appearances

Sonic Jam (

In Sonic Jam (, the Egg Poison appears as one of the bosses in Emerald Hill Zone.


The Egg Poison is the boss of Chemical Plant Zone Act 2 in Sonic the Hedgehog 2, its various ports and remasters, and the lock-on game Knuckles the Echidna in Sonic the Hedgehog 2, and the second boss overall in these games. It is also the second boss of Boss Attack Zone in the 2013 remaster of the game. In the original Sonic the Hedgehog 2, the Egg Poison is fought with Sonic and/or Tails, while in Knuckles the Echidna in Sonic the Hedgehog 2 and the 2013 remaster of the game, it can also be fought with Knuckles.

Boss guide

The boss battle takes place on a yellow platform over a lake of Mega Mack. On either side of the arena, there are three platforms that flip over and drop anyone standing on them into the Mega Mack, which spells instant death. The player has to time their jump to the vehicle to avoid falling into the Mega Mack ocean.

During the battle, Dr. Robotnik will fill the Egg Poison's canister with Mega Mack from the lake beneath (although the liquid in the canister appears blue rather than purple). When the canister is full, the doctor will attempt to dump the Mega Mack on top of the player. After that, Robotnik moves to the other corner to fill another amount of Mega Mack to the canister and repeats the same pattern.

The Egg Poison takes eight hits to defeat, after which the player can open up the Capsule and finish the Zone.


Name Artist(s) Length Music track
"STH2 Boss 〜Mega Drive version〜" Masato Nakamura 2:14


  • The Egg Poison can actually be defeated very easily by jumping right up to it at the start of the battle and bouncing off it repeatedly while against the right edge of the screen.
    • By doing so in the 2013 remaster of the game, the player will earn the "Bop Non-stop" achievement.
Sonic2 CPZ Robotnik goop drop.gif
  • In a prototype version of Sonic the Hedgehog 2, sprites of Robotnik have been found where he takes the chemicals and accidentally dumps them on himself. This might have been an ending sequence for this zone, but was removed.





  1. Flynn, Ian; Sega (8 December 2021). Sonic the Hedgehog Encyclo-speed-ia. Dark Horse Books. ISBN 978-1506719276. "Boss: Dr. Eggman pumps up Mega Mack into his Egg Poison and drops buckets full of goo as the floor folds away."
  2. (in Japanese) ソニックメガコレクション最強攻略ガイド. Shogakukan. 1 March 2003. p. 69. ISBN 978-4091060907.

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