Darla (Julie Benz) appeared with the Master in the very first episode of Buffy the Vampire Slayer, and she is later is revealed to have been the vampire who made Angel who in turn made Drusilla. So when Drusilla remakes Darla in ‘The Trial’, Darla is both her vampiric grandmother and her daughter: no wonder they were a strange pair.
Somehow Darla survived her encounters with the Slayer to become one of the very few recurring vampire characters in Buffy, and then made the transition to being a recurring character in Angel.
The vampire designs evolved from concepts designs created by the Burman Studios.
Until 2002 Harlow FX created the makeup effects with Todd McIntosh as makeup supervisor.
Robert Hall (Almost Human) was then (Buffy seasons 6 & 7 & Angel seasons 3 to 5) in charge of the makeup effects with Dayne Johnson as makeup supervisor.