Lieutenant Esteban Rodriguez was a Starfleet science officer who served aboard the USS Enterprise under Captain James T. Kirk. One of his jobs was collecting plant specimens. Rodriguez was a close friend of Angela Teller.
In 2267, Rodriguez was one member of the landing party assigned to explore the Shore Leave Planet. During his visit there, his imagination gave form to a flock of birds, a Bengal tiger, and later a Japanese Zero warplane that strafed and apparently killed Angela. (TOS: "Shore Leave")
In the Lost Era novel Serpents Among the Ruins, Rodriguez was "officially" the captain of the USS Agamemnon, with Mike Paris, Tom's grandfather, as his first officer, and was killed along with his entire crew when the ship, along with 13 Starfleet outposts, was destroyed in the Tomed Incident – but in reality, like all 4,000 other supposed casualties of the catastrophe, he had been killed at some point in the year before, and their deaths were covered up, with records falsified to make it appear that they had perished aboard the Agamemnon and the lost bases.