Oscar Cthulhu

Oscar Cthulhu (オスカー・クトゥルー Osukā Kutourū), also known as the "Great Old One" ( 旧支配者 グレート・オールド・ワン Gurēto Ōrudo Wan), is a character introduced in Ghost Reaper Girl series.

Trivia

 * His last name and title referenced to a cosmic entity Cthulhu from H. P. Lovecraft's The Call of Cthulhu.