Malachi and Kodor

History
Malachi and Kodor were Great Old Ones which were present on Vandaria.

They created Vandaria as sort of an experiment, similar to Vortis and the Animus (Twilight of the Gods), creating a species similar to men and a Canid form of life that would evolve to become the Reyns.

They eventually went into a form of hibernation, not before becoming gods to the Reyns, with one of them being named Saekos.

Sometime after the Second Doctor defeated Yog-Sothoth in 1930s Tibet (The Abominable Snowmen), Malachi and Kodor awakened for the first time, trying to regain control of Vandaria, however, they were stopped by a group of Reyns who would later meet Faction Paradox (The Crimson Flag (Faction Paradox)).

They next awakened during the 23rd century, first influencing Captain Francis into committing genocide over the Red Reyns, next trying to use him to assassinate Virmir and Lucille, however the arrival of Korrek stopped them from doing this, Malachi and Kodor later tried to influence the Doctor and Mel into giving them the TARDIS so that they could remove Virmir and Lucille from time itself, briefly making the Doctor into a Reyn, The Doctor fought off Malachi and Kodor, and, with the help of Jacqui de Saldis, sealed off Malachi and Kodor for 23,000 years (The Crimson Flag).

Appearance
In their first awakening, they resembled dragons, in their second appearance, though, they tried to recreate their original physical form, being stripped of it sometime between their hibernation and first awakening

Their physical form resembled two humanoid figures wearing armour, they had glowing eyes, with Malachi having pink eyes and Kodor having blue eyes, during the reconstruction, they took on a skeletal form, they then gained flesh from colonists killed during the battle between Korrek and the Reyn Empire, taking on a gaunt form with slit noses, with pinkish skin and red, bloodied flesh.

Trivia

 * Malachi and Kodor are one of the only characters to have featured in both the Crimson Flag webcomic and in the episode of Doctor Who, though under different names.