"Ytheleus" is the second part of a name, "Sisela Ytheleus 1/2", belonging to a spirited type D-4 military drone of the explorer ship "Peace Makes Plenty", a vessel of the Stargazer Clan, part of the Fifth Fleet of the Zetetic Elench - from Iain M. Banks' fifth Culture novel, _Excession_.

> "One should always be prepared for every eventuality, even if it's getting shafted by a dope with bigger guns."