Downunda is the continent of Australia on Mobius and home of the Downunda Freedom Fighters. It was also the continent which Echidnaopolis existed on before the Echidnas used the power of the Chaos Emeralds to send their city airborne in order to avoid its destruction by the White Comet. During the ten year rule of Dr. Ivo Robotnik, Downunda was controlled by Robotnik's sub-boss Crocbot. After the despot's demise, the Downunda Freedom Fighters managed to overthrow Crocbot and regain the continent's freedom.
After the formation of the Eggman Empire and the expansion of its territories, the continent of Downunda remained untouched. Knuckles the Echidna speculated this was due to the continent lacking any strategic value.This changed in the months following Sonic's return from space when the former Freedom Fighter, Bill became the new Sub-Boss of his "own free will" and led his fellow platypuses to serve the Eggman Empire with cybernetic enhancements and equipment from Dr. Eggman, forming an earlier branch of the Dark Egg Legion.
The status of the Downunda Freedom Fighters was uncertain for some time as they were unable to respond to Princess Sally's distress call during the newest Enerjak's rampage in New Mobotropolis. However, Dr. Eggman was scrambling any outgoing or incoming signals, so the lack of contact with them may have been entirely for that reason or possibly also due to them combating the Platypus Dark Egg Legion. Bill would then plot against Knuckles with Dr. Finitevus at the Crater Rim shortly before the Guardian set out after his enemy. Dr. Finitevus later chained Angel Island to Downunda for unknown reasons. A horde of upgraded Wing Dingo robots also assaulted Shrine Isle in an attempt to steal the Master Emerald, leading to the question of whether or not Dr. Eggman's influence had left the continent even though Crocbot was gone. It was soon revealed Eggman did indeed attempt another takeover, this time with locals as his enforcers. The platypus of Downunda rallied Duck Bill to lead them, setting up base in the Great Crater and made members of Eggman`s Dark Egg Legion. Cybernetics and blasters were supplied and they began the counquest of the land down under. Due to poor leadership they gained little progress other than the crater.
The Downunda Freedom Fighters
Duck "Bill" Platypus
The Downunda Dark Egg Legion
Vector the Crocodile