Socket(called Sock only by her friend Papyrus) is a female Eelektross of unknown age. She used to be the head of The Royal Thieves, before faking her death.
Papyrus- Though their exact relationship was unknown, they're friends, as stated by Papyrus. To counter this, however, Socket has said before that she "has no friends". Papyrus may have been an exception.
Socket is a dangerous and slightly psychotic murderer and theif. In battle she would strike with speed and precision, leaving most foes in her wake dead or heavily injured within a few attacks. She eventually was slain in a battle against Corma and Vivi, only to be shown to have somehow survived.