Oxymoron

A stupid person with bad skin problems.

Poor Norman he has the intelligence of an amoeba and a face only a mother could love.
...yeah poor Norm, he's an Oxymoron.

Grrr

Something someone says when they want appear aggressive or intimidating (in a positive or negative way) but has the opposite effect, inducing laughter or pity.

yeah baby, I'm a bad boy tonight...grrr

or

I'm really scary...grrr