Mutant muckdwellers are enemies in Going Commando. They are small, reddish, three-eyed mammalian mutant creatures with long ears native to Oozla, found near the Megacorp Outlet area. They move by bouncing across their ground, as they have small, stubby legs. They attack by emitting poisonous gas in a short range, compared by Megacorp to the Horrible Sulphur Beast of Klor, with the primary difference being that the gas originates from their mouths.
Ratchet encountered them during "Find the store entrance", during which they would kill nearby Megacorp employees in the wild, and "Explore the swamp ruins". They were often found alongside the mutant firefly and mutant swamp beasts, though they were not found inside the outlet itself. They bounce around in groups before seeing Ratchet, at which point they will attack by bouncing towards him and spraying poisonous gas at a short range. They are relatively weak enemies, but mostly pose a threat due to their large numbers. Using any weapon will eliminate them, though in instances where their numbers become too great, resorting to the Gravity Bomb may be necessary and can make quick work of their large groups.
Mutant muckdwellers briefly appeared in Up Your Arsenal as a chess piece.