Evil minions also known as goblins are creatures who steal or raise children of humans to be their leaders and to guide them on evil deeds. Humans raised by goblins are intelligent and good in the art of war and they have the loyalty of hordes of goblins to their sides. A human leader is an inspiring figure for goblins and goblins are kindred to the human.
The goal of the goblins is to grow, reproduce, gain new land and most importantly destroy the human species. Human leaders are grown to recognize goblins as their family and see the people outside goblin colonies as foes. Goblins live in colonies with castes, they have a few queen who's job is to produce new members of the colony. They are related to primates, but shorter, just as intelligent as humans and have a greenish skin, some darker than others.
The image below shows what goblins looks like.
This behaviour of evil minions is not recent, but it's a thing evil minions have always done during their evolution. Ancient primitive goblins used to steal children of human ancestors and this behaviour was kept through years of evolution up to this day.
Why would a creature steal the offsprings of a closely related animal to raise them as leaders?