Mega Muck, also spelled as Mega-Muck, is a substance that appears in the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics. It was an artificial liquid used by Dr. Ivo Robotnik, and later by Dr. Eggman.
In the realities created by the Genesis Wave, the Mega Muck's properties were completely overhauled. A purple liquid with texture seemingly identical to that of water, the Mega Muck is described as a "viscous polymer with toxic properties" which is poisonous to living beings.
During Operation: Clean Sweep, the Mega Muck became a deadly chemical agent due to the Genesis Wave. While Sonic, Sally, Tails, Antoine and Boomer traveled through the Chemical Plant Zone, the group nearly drowned in Mega Muck when the substance started flooding their route.
The Mega Muck later resurfaced in the Skull Egg Zone after the launch of the second Genesis Wave, with the same properties it had during "Genesis." While searching for the Roboticized Masters, Sonic, Tails and Mega Man would cross a lake of Mega Muck.
- Note: From this point, the Mega Muck's history continues from its new existence in the altered timeline.
- The Mega Muck is based on the Mega Mack which was first seen in Sonic the Hedgehog 2. However, its properties when first introduced were more similar to the Mega Muck in the Sonic the Hedgehog television series.