Frank Booth is a fictional character and the main antagonist in David Lynch's 1986 psychological thriller Blue Velvet, portrayed by Dennis Hopper. A violent drug dealer, he has kidnapped the family of lounge singer Dorothy Vallens, holding them hostage in order to force her into becoming his sex slave. Their encounters are characterized by Frank huffing an unknown gas from a tank he carries with him. This causes him to exhibit a split personality between two individuals he identifies as "Baby" and "Daddy," whose personas he assumes to engage in acts of ritualistic rape. One of Frank's associates is a police detective nicknamed "The Yellow Man" (for his distinctive yellow sport coat), who helps Frank by killing rival drug dealers. The Yellow Man later steals their supplies from the evidence room, so Frank can sell them himself.