The Invisible Man is a human englishman who developed and created a serum to become invisible and who since that day is being hunted and investigated by the Holy Order and the Vatican.
History[]
Van Helsing: From Beneath the Rue Morgue[]
When Dr. Moreau talks to Van Helsing about his Chimera creation, Beathán escaped using his invisibility ability that he obtained after the "English Man Serum". Van Helsing recalls a Vatican report about an Invisible English Man seen in West Sussex. (Obviously referring to Griffin, the Invisible Man)