This spell is used only once by Lord Voldemort on Severus Snape. It is implied to be some form of torture spell as payment for Snape's traitorous behavior, though it is not lethal as promised by Voldemort. Hyakuju means 110 in Japanese, and 110-Montauk is the name of a containment procedure in the popular supernatural collaborative writing project SCP Foundation, specifically mentioned in SCP-231's entry. The nature of 110-Montauk is not totally known, but it is thought to be quite horrifying, which would imply that this spell is a similar form of torture to whoever falls victim to it.