So dangerous, even King Cold himself told Frieza not to mess with him. Which makes me wonder, what was the point in Frieza getting his revenge on Goku if he knows that he's the one who defeated Majin Buu.
Plus we all know how his first attempt of revenge went. He got killed by Trunks. So what made him think his revenge would work again. Looks like the Saiyans being stubborn rubbed off on Frieza.