Tania Tobias was a human female in Starfleet in the 24th century. She was the daughter of Lieutenant Tobias, chief engineer of the USS Intrepid.
Tobias enrolled at Starfleet Academy in 2357. While there, she formed close friendships with fellow cadets Soleta, Zak Kebron, Mark McHenry and Worf.
Tobias was among the Academy contingent that was sent to the colony on Dantar IV, when the Federation/Klingon co-venture was experiencing problems. When the colony was the victim of a sneak attack, Tania stayed behind in the colony when the evacuation ships hit capacity. Tobias, her squad, and a squadron of Klingon cadets defended the outpost from its Brikar attackers until reinforcements arrived with the USS Repulse.
Tobias' first assignment out of the Academy was aboard the USS Aldrin. She was part of an away team that was attacked by Romulan smugglers in the year 2362. When team leader Lieutenant Ashanté Shimura was injured, Tobias became team leader. She and Ensign Worf tracked one of the attacking Romulans, V'Ret, after their ship had crashed. To Tobias' dismay, Worf did not hesitate to use lethal force.
By the late 2370s, Tobias was attached to the "Worlds Within Worlds" project, which was designed to offer an alternative to terraforming by using a concept similar to that of a Dyson sphere. While working on the project, Tobias suffered an unexplained mental breakdown that left her prone to having incoherent screaming fits.
Captain Mackenzie Calhoun decided to take a chance on Tobias, and had her assigned to the USS Excalibur as conn officer. Unbeknownst to her, Calhoun instructed the ship's computer to keep a constant watch on her vital signs in case she were to have an episode.
When the Excalibur was at Priatia and in the extra-dimensional realm of the Teuthis and Bolgar, she seemed to be able to sense the comings and goings of the aliens, an ability apparently tied to her experience at Worlds Within Worlds.