Thelma was a siren, ressembled to a octopus-like woman. She was also member of a pack residing in San Franscisco, whom members use hypnotizing song for to lure and devour males customers into bars and clubs like Xander Harris and the vampire Spike that she attract under the appeareance of a young blond woman. However, the two men, partially saved by the ghost of Anya Jenkins, succeed in going out of the bewitchment. Also, the boss lady runs away, loading her minions to eliminate them.