High brain

From Tardis Wiki, the free Doctor Who reference

The term "high brain" was used by the Krotons to denote high intelligence, the term being used to refer to themselves and sufficiently advanced individuals like the Second Doctor and Zoe Heriot.

The Kroton Absolute was led by the four highest brains, contained in the citadel of the First Lattice. (PROSE: Alien Bodies)

A Kroton Dynatrope required four high brains to pilot it. When one Dynatrope came under enemy fire, two of its crew were exhausted and the other two were forced to make an emergency landing. (TV: The Krotons)