To what animal does Scout compare Mr.Ewell? How is the comparison fitting?

Scout compares him to a little cock of a man,

"In answer to the clerk's booming voice, a little bantam cock of a man rose and strutted to the stand, the back of his neck reddening at the sound of his name."

Ewell is like a little insignificant cock bird who is getting his only moment of fame he will ever have.