Another ego-man, but my personal favorite. Frieza doesn't give a damn if you die, and it will mean absolutely nothing to him. He probably won't even think about it while he's killing you. He is extremely powerful, and virtually indestructable. He has four different forms, each one more than twice as strong as the last. He killed the entire saiyan race at one shot when he feared they would one day cause a problem, and killed many of the Nameks as well.
My two cents: Consider this. Most people look at the fight between Goku and Frieza and say: Yeah, Goku won by a landslide, he was a super saiyan!! But I poo-poo these people. Think about it. Frieza only lost because he got careless and got chopped in half. If not for that, he would've won. It goes like this: Frieza was at under half his power when Namek exploded, but still lived afterwards. If he wouldn't have got sliced in half, he would've continued fighting Goku. They would've been there for another 5 episodes or so. When Namek would've exploded, Frieza would've been fine(if he survived it when nearly dead, he'd be fine here), and Goku would've died. That simply would've been it.