High Spec grants Nezu, an animal, unparalleled intelligence, perception, and comprehension that far surpass that of humans. Through this Quirk, Nezu became capable of thinking, speaking, and acting like a person.
Due to his unfathomable intelligence, Nezu is capable of instantly formulating incredibly intricate strategies; for example, from a single vantage point, he can create a chain reaction of destruction to wreck an entire industrial zone with just one well-placed wrecking 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 School, a top hero school.
Because of his 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.