Ice Lord

Ice Lord was the higher caste of the Ice Warriors. (COMIC: Descendance)

While in a 23rd century museum on Deimos, Tamsin Drew pointed out an Ice Lord wearing traditional Ice Warrior burial regalia. (AUDIO: Deimos)

Isskar was once promoted to the rank of Ice Lord, and the Fifth Doctor detected this based on his appearance alone. (AUDIO: The Judgement of Isskar)

An Ice Lord was frozen and imprisoned on Shada. (PROSE: Doctor Who and the Krikkitmen)

Other references
In the video game Happy Deathday, played by Izzy Sinclair on the Time-Space Visualiser, an Ice Lord was among a host of "every single enemy" that the Doctor had ever defeated, who were assembled by the Beige Guardian and pitted against the Doctor's first eight incarnations. (COMIC: Happy Deathday)