Dabura was a ruler of the Demon Realm for thousands of years. Dabura was under a spell by Babidi. Dabura turned Piccolo and Krillin into stone and killed Kabito, who was revived. Dabura also battled Gohan (while in his Super Saiyan 2 form). When Majin Buu was revived, he told insults about and turned into a cookie. Dabura is now in heaven, being good now.
Dabura in Heaven
Dbaura's special ability is Stone Spit, which when touched on skin, can turn a person into stone.
Dabura using Stone Spit on Krillin