mackerel - A fish that's mostly used to describe the kind of person who

A fish that's mostly used to describe the kind of person who eats lunch at 10 AM and still smells like breakfast.

My teacher said, 'You're like a mackerel, always showing up late.'

I told my brother he was a mackerel because he forgot to do his homework.

My friend's dog is a mackerel because it eats my shoes.