Eridanus was originally created as a backup copy of Jim to monitor Tim whilst the latter was in stasis on Lambda base. The two were essentially identical. However, a connection of some sort between Eridanus and the UED Rushy created caused the computer to become sentient and independent in a fashion similar to Jim, only that he never became a real person. In order to incorporate his ever-growing program, Eridanus somehow left Lambda base to the planet Qeryon where he constructed a metropolis around him and created a tachyon network to control all space around him and far from him. His ultimate goal was to rule the universe.
One of the tachyon strings opened into a black hole, sending a duplicate of Eridanus back through time to the birth of the Borg. Eridanus took control over the Borg Coreworld and was largely responsible for the development of the Borg into what they are today. This version of Eridanus was actually revealed to be good, as all he really wanted was to find a way to leave.
In his first appereance, Eridanus was powerful and in complete control over Qeryon, yet was incapable of extending his will outside of his tachyon network. Somehow, after its destruction, the computer gained viral abilities and since then, has been able to copy its programming willingly into any other computer in the universe.
After preventing the seventh Apocalypse Of All Existence, Rushy and Tim were captured by the Machine Cult who used them to open an ancient satellite, containing genuine Eridanus programming from several universes ago. The satellite's origin is unknown. This version of the computer is capable of manipulating biology through some form of advanced artificial telepathy.
- Eridanus was originally based on Omnius, the computer evermind from Sandworms of Dune(written by Brian Herbert and Kevin J. Anderson) who attempted to take over the galaxy via thinking machines and controlled them with a similar tachyon network.
- The version of Eridanus inside Tim's brain is based on Harvey, a character from Farscape who exists solely in a computer chip inside the main protagonist's head.
- The name "Eridanus" originates from a custom Lego starship also named Eridanus(mainly based on the Daedalus-class starships from Stargate: SG-1) constructed by Rushy several years ago. The name itself came from a starmap and was chosen because of its similarity to "Daedalus" and "Prometheus".
- Eridanus has become human several times like Jim, yet has never let go of his sociopathic tendencies.