10 Star Trek Characters Who Appeared On Multiple Series
9. Worf And Miles O'Brien
At first glance, these two seem to have little in common. One is a Klingon warrior who was raised by humans and eventually became the first member of his species in Starfleet. The other was an unnamed Starfleet officer on Picard's Enterprise who became Transporter Chief Miles O'Brien. But these two characters do have common ground, specifically that they both moved from the Enterprise-D to Deep Space Nine.
On The Next Generation, O'Brien was one of the more developed secondary characters, with several episodes focusing on him. He was as close to being a primary cast member as you could be without actually being one. He eventually married a civilian on the Enterprise-D named Keiko, who also moved to DS9. O'Brien was a main character on that series from moment one.
Worf, on the other hand, did not arrive until season four. He became the Chief of Security on the Enterprise-D after the death of Tasha Yar, transferring to DS9 after the destruction of the Enterprise and becoming their Strategic Operations Officer. Between TNG and DS9, Worf appeared as a series regular in 11 seasons of Star Trek TV shows and has been in more episodes than any other character.
Both Worf and O'Brien have played key roles in the Star Trek universe. O'Brien adds an important human element to series that can get bogged down in the space opera aspects. Worf is also a key component to the Star Trek universe as it's through him that fans get an amazing view of the Klingon Empire.