The thrill they get while trolling

Their lack of concern and compassion for others. Toxicity is often found amoungst the narcissistic

selfishness
and dissatisfaction of self
evil genes
bad parenting
lack of empathy

bioamplification

The effect they have on you

Bad experiences

PDs.

Anger, frustration, not being able to get their own petty way

Hmmmm .... they engage in in ongoing malicious alienation .... telling friend A what's wrong with friend B and telling friend B what's wrong with friend A. If and when Friend A meets friend B, they already dislike one another.

Misery loves company?

Resentment

smell and std

Your judgmental view of them

It's fashionable today to say it's all based on early trauma, but I believe some people are just born assholes. Have you ever fed seagulls, and one of them bullies all the others around? That's what a toxic person is.