Tuvix

Tom Wright was eager to pursue the role of Tuvix when he first heard about it. While he had not previously watched Star Trek: Voyager (1995), he was acquainted personally with Tim Russ and Ethan Phillips, having often auditioned for the same roles as the former and having appeared in a play with the latter. When he originally read for the role, knowing little about Tuvok and Neelix, Wright instead based his portrayal on his knowledge and experience of Russ and Phillips.

Though he is the more senior officer, Lieutenant Hogan addresses Ensign Kim as 'Sir'. This is because whilst Hogan is senior in rank, Kim is a Bridge Officer and part of the command crew. In this instance, Hogan is addressing Kim's seniority by position not by the rank on his collar.

This has been long held in terrestrial armies and navies for centuries up into the current times. An Officer In Command (OIC) is deferred to even though their actual held rank may be lesser. It is done to keep the command structure of the vessel intact. Also, the episode identifies Hogan as a crewman, making Kim a higher rank than him. His rank is inconsistently given as crewman, ensign and lieutenant in his various appearances.

Referenced in Star Trek Timelines (2016)