The Savant was an organic technological device from Epsilon Eridani.
The Savant was shaped like the letter Y. It had dirty yellow feather-scales and a truncated mahogany-coloured beak. The Savant had no visible eyes, ears or nose. The only Earth food it would eat was Kosher Pareve fruit loops.
The creature was designed to hack any system, mechanical or organic. It could create a programme that would replicate and transmit itself. This would render the affected system, whether a computer or a brain, susceptible to control.
The Eridani were sending it to their colony near Van Maanen's Star to test its effectiveness. However, when the spacecraft it was onboard came through the solar system, the ship's navigation was disoriented by the radio traffic from Earth and crashed on the planet.
The Savant went through several hands after that. Eventually the Sixth Doctor, with help, found and deactivated it. (PROSE: Blue Box)