What makes someone an "ugly person on the inside"?

Tomatoes

Someone who has a narcissistic personality, people who have an inflated sense of their own importance, a deep need for excessive attention and admiration, troubled relationships, and a lack of empathy for others.

Cruelty

Self centered pride has got to be the worst

Dishonourable

Disloyal. Liars. People with adjendas. Those types.

Manipulative, conceited, liars etc.

dishonesty in general, like liars and thieves. lack of compassion also.