|Planet of Origin:||Earth|
|Date of Death:||During the Long Night|
|Age:||Unknown, but young|
|Chronological and General Info|
|Affiliation:||Nietzschean Authority on Earth|
Siobhan was a human cousin of Seamus Harper who lived on Earth. She and her twin brother, Declan, were infested by Magog when they were very young, and were the only members of their family who were infested. Their parents, along with their extended family (including Harper), decided to kill them instead of letting them hatch; to not only save them the pain and suffering that would occur but to also slow the spread of the Magog.