Memory Alpha
Memory Alpha
Multiple realities
(covers information from several alternate timelines)
B'Elanna Torres, Human-Klingon faceoff

B'Elanna Torres, a hybrid split into Klingon and Human halves

A hybrid or mixed species was the end result of mixing two or more different species in the biological process of reproduction. Klingons referred to hybrids derogatorily as a mongrel. (VOY: "Barge of the Dead", "Prophecy") Spock was also derogatorily referred to as a half-breed on a number of occasions. (DIS: "If Memory Serves"; TOS: "What Are Little Girls Made Of?", "This Side of Paradise", "Day of the Dove")

Biological aspects[]

Because of the common genetic ancestry of most of the species of the Milky Way Galaxy by way of the ancient humanoids, many species were able to interbreed with or without the help of genetic technology. (TNG: "The Chase")

According to Doctor Phlox, Humans and Vulcans were quite similar. (ENT: "Demons") In fact, Bethany, a Human/Skagaran hybrid, was one of the first known hybrids encountered by Humans from Earth, confirming that such interspecies breeding was possible. (ENT: "North Star")

Societal aspects[]

Tora Ziyal, 2373

Tora Ziyal, a Bajoran/Cardassian hybrid

In some cultures, children who are born as a result of interspecific relations were rejected by the society of both races. For example, Bajoran/Cardassian hybrids were often rejected by both Bajorans and Cardassians. (DS9: "Indiscretion", "Return to Grace") This was, however, the same treatment usually received by Cardassian orphans, as well. (DS9: "Cardassians")

During the mid-22nd century, before such things were commonplace, those behind Terra Prime, such as John Frederick Paxton, believed that Elizabeth, a test tube baby-hybrid of a Human and a Vulcan was "a cross-breed freak," asking, "How many generations before our genome is so diluted that the word "Human" is nothing more than a footnote in some medical text?" (ENT: "Terra Prime")

Personal aspects[]

Spock, 2266

Spock, a Vulcan/Human hybrid

As noted above, Spock, a Human/Vulcan hybrid, had many personal demons when it came to his being.

In 2266, he shared with Doctor Leonard McCoy that "being split in two halves is no theory with me, Doctor. I have a Human half, you see, as well as an alien half, submerged, constantly at war with each other. Personal experience, Doctor. I survive it because my intelligence wins over both, makes them live together." (TOS: "The Enemy Within")

Examples of interspecific reproduction[]






  • Cardassian/Bajoran
    • See above
  • Cardassian/Bajoran/Human
    • See above
  • Cardassian/Kazon





The production notes from Star Trek: Enterprise stated that the creators were planning to reveal T'Pol as a Romulan/Vulcan hybrid if the series had continued.

Saavik was intended to be half-Romulan in Star Trek II: The Wrath of Khan, but a scene establishing this was cut.


  • Talaxian/Mylean
    • Alixia (presumably ⅞ Talaxian, ⅛ Mylean)
    • Neelix (⅞ Talaxian, ⅛ Mylean)
  • Talaxian/Mylean/Vulcan
    • Tuvix, a fusion of Tuvok and Neelix, was created by a transporter malfunction with a symbiogenetic orchid.


  • Trill/Bajoran
    • See above
  • Trill/Human
  • Trill/Klingon
    • See above


In the first draft script of Star Trek III: The Search for Spock, another Vulcan/Human hybrid, called Galt, was to have been introduced.


See also[]

Background information[]

In an initial story outline of TOS: "Charlie X", Charles Evans was referred to as a Human/Ferndok hybrid, since his mother was a Ferndok (a species which, during the episode's development, was later renamed Thasian).


In the novel The Ashes of Eden, Kirk discovered the colony world of Chal, a planet briefly colonized by the Romulans and Klingons during an alliance, populated by genetically-engineered Klingon-Romulan hybrids.

External links[]