Tim Tuna is a TV retuner who worked with Tails during a mission to stifle the Doctor Robotnik Appreciation Tribe. D.R.A.T. had staged a television programme that subliminally taught children to admire Doctor Robotnik and encouraged them to play as the side of Badniks in play fights against "Sonic the Hedgehog". Tim Tuna was enlisted to block the event and instead broadcast a message carrying the gang's real intentions.
Tuna is simply a fish contained in a suit, his head visible through a fish bowl that keeps him wet. To this end, Tuna heavily resembles a DrakonProsecutor. Somebody very similar met Tails previously in the Echo City Zone, thanking him for saving their town before it was even attacked.