Ant Man

Ant man, one of the founding members of Avengers, has the ability to shrink to the size of approximately one-half inch in height, by means of the subatomic particles known as the Pym Particles or can transform himself to 100 feet tall when he discovered Pym Particles which interacted with his brain to enable him to grow to gigantic height.

He is also equipped with the Cybernetic Helmet which permitted him to achieve rudimentary telepathic communication with ants and other higher insects and to control their minds.