"The Strange Case of Dr. Jekyll and Mr. Hyde" was a novel by Robert Louis Stevenson about a man named Henry Jekyll who turns into a murderous lowlife named Edward Hyde after drinking a potion.
History[]
When Proteus appeared in our world, ghostly versions of Captain Ahab, Mr. Hyde, and The Frankenstein Monster were haunting a library. All of the ghosts were captured. Then when Slimer was looking for information in the Containment Unit, Mr. Hyde can be seen with Captain Ahab again.