High Spec grants Nezu, who was formerly a regular animal, unparalleled intelligence, perception and comprehension far surpassing that of humans. Through this Quirk, Nezu became capable of thinking, speaking and acting like a person.
Due to his unfathomable intelligence, perception and comprehension, Nezu is capable of instantly formulating incredibly intricate strategies; allowing him, from a single vantage point, to destroy an entire industrial zone along a designated path with just one well-placed construction ball smash. This same intellect also grants him flawless leadership skills, which are acknowledged by the fact that he is the principal of U.A. High, a top hero school.
Because of his acquired intelligence Nezu can perfectly recall anything. As such, Nezu holds grudges from being experimented on, feelings that are exclusive to the human species, which might interfere in his thought processes.