First One (Masters of the Universe)

The First Ones are a mysterious race of sapient creatures which dwell underground on planet Etheria, and are regarded as the original inhabitants of the planet, long before the rise of other civilizations.

Biology
Physically, the First Ones appear as giant amorphous creatures made entirely out of flames. It's not known if this represents their original appearance, or even their actual appearance as opposed to a mere projection.

They have mastery over extremely advanced magic, so powerful that they're the only ones capable of restoring a damaged Sword of Protection to its normal state.

The knowledge displayed by them suggests either a supernatural awareness of all that happens on Etheria or the ability to effortlessly read minds.

Appearances

 * She-Ra: Princess of Power, s01e21, "The Stone in the Sword" (1985)