Meron

The Meron were a fish-like species who were at war with the Jixen.

Biology
The Meron were light blue-skinned, fish-like humanoids with three fins on their enlarged craniums and two on the top of their necks. They had four black tendrils on their chin and three webbed fingers on each hand. The Meron reacted to the Jixen battle shriek; it caused them great pain and disrupted their human disguises. (TV: Liberation)

Technology
The Meron used a trident-shaped weapon which emitted a green energy beam. They also had the ability to take a human form. (TV: Liberation)

History
The Meron fought a centuries-long war with their sworn enemies, the Jixen. Whole planets were destroyed in the conflict. The Jixen were winning the war but they were eventually defeated (TV: Liberation) when the Korven turned the tide by supplying the Meron with energy weapons which they then used to take the Jixen's "rightful home". (TV: Hound of the Korven)

In the mid-21st century, a Korven named Lomax from the year 50,000 took control of the British government and created the Department so the Korven would soon be able take over. He was aided by Thorne, who was originally human but was implanted with Meron DNA. He was the governor of Dauntless Prison. (TV: The Eclipse of the Korven) Two Meron disguised as humans also worked in the Department in Dauntless Prison so they could take DNA from the alien prisoners to create Project: Trojan. They arrived at Gryffen Manor where they gave Alistair Gryffen a component to the Korven Space-Time Manipulator. An accident caused the hound of the Korven, K9 Mark I, and four Jixen to be sent through. K9 self-destructed and regenerated into a new form to kill the Jixen. (TV: Regeneration)

One Jixen survived and was able to track the two Meron down. When K9, Starkey, Darius and Jorjie were investigating the Dauntless Prison, K9 and Starkey encountered the Jixen. Soon after trapping it in a cell, one of the Meron arrived, revealed his true form and attacked K9. When he tried to attack Starkey, the Jixen used its scream and frightened him off. (TV: Liberation)

Later that year, Lomax began the Korven invasion of Earth. After the invasion force was destroyed, the completed Trojan was sent by Thorne to destroy K9. K9 used a recording of a Jixen call to cause Trojan's Jixen DNA to fight its Meron DNA, sending it toppling over and crushing Thorne. (TV: The Eclipse of the Korven)

Behind the scenes

 * Only one Meron was shown in his true form in Liberation, but two actors were credited as Meron and Department technicians. In an earlier scene, the Meron from later is seen experimenting on an alien alongside another man, who is most likely the second Meron.
 * The two Meron also appeared in their human disguises in Regeneration, despite not being credited.