Squealer is a queerat, an intelligent species that work as servants to humans. Like others of his species, he is small, has the appearance of a giant rat, but is very sly and astute. He is the representative of the Robber Fly, a small colony of queerats.
His ideals are freedom, equality between human and queerats and the end of the monarchy system inside of the queerats colonies, where the queen is the absolute ruler.
He helps Saki and her friends to escape from the wild queerats that were pursuing them.
Later, he shelters Maria and Mamoru from the tainted cats in his colony. But his ultimate goal was to obtain a human child from Maria and Mamoru, which when matured will gain the ability to use cantus. With the child Squealer plans to start a revolution against the humans.
Once Squealer obtained the child, he had Maria and Mamoru killed and their remains were returned to the village to quell the suspicion of the humans. By this time, Squealer is the leader of an alliance composed of equality seeking queerats and the supreme commander of the army in the alliance. Squealer then secretly raised the child to fulfil his ideals of conquest and dominance over the humans. After around 10 years, he uses the child in combination with his army of queerats, in an attempt to wipe out the human race.