The Leopard Men

In ancient Egypt, the leopard was esteemed as an aspect of divinity and associated with the god Osiris, the judge of the dead. For many African tribes, the leopard is a powerful totem animal that is believed to guide the spirits of the dead to rest.
For many centuries a leopard cult has existed in West Africa, particularly in Nigeria and Sierra Leone, wherein its members kill as does the leopard, by slashing, gashing, and mauling their human prey with steel claws and knives. Later, during gory ceremonies, they drink the blood and eat the flesh of human victims. Those initiates who aspire to become members of the cult must return from a night's foray with a bottle of their victim's blood and drink it in the presence of the assembled members. The cultists believe that a magical elixir known as borfima, which they brew from their victim's intestines, grants them superhuman powers and enables them to transform themselves into leopards.
The members of the cult kill on the slightest pretext. Perhaps one of the members became ill or his crops failed. Such misfortunes as these would be sufficient to demand a human sacrifice. A likely victim would be chosen, the date and time of the killing agreed upon, and the executioner, known as the Bati Yeli, would be selected. The Bati Yeli wore the ritual leopard mask and a leopard skin robe. It was preferable that the sacrifice be performed at one of the leopard cult's jungle shrines, but if circumstances demanded a more immediate shedding of blood, the rite could be conducted with the ceremonial twopronged steel claw anywhere at all.
The first really serious outbreak of leopard-cult murders in Sierra Leone and Nigeria occurred shortly after World War I (1914–18). At that time, it was believed the cult was suppressed by the region's white administrators because many of its members were captured and executed. However, in actual fact, the leopard men simply went underground, continuing to perform ritual murders sporadically every year over the next two decades.
In 1946, the leopard men became bold and there were 48 cases of murder and attempted murder committed by the leopard cult in that year alone. And it soon became obvious that, much like the Mau-Mau in Kenya, the leopard men had begun directing many of their attacks against white men as if to convince the native population that the cult had no fear of the police or of the white rulers. The trend continued during the first seven months of 1947, when there were 43 known ritual killings performed by the leopard cult.
Terry Wilson had been district officer of a province in Eastern Nigeria for only six months when, early in 1947, he discovered that the leopard men had begun operating in his jurisdiction, claiming mainly young women as their victims. When Wilson raided the house of a local chief named Nagogo, his men found a leopard mask, a leopard-skin robe, and a steel claw. Acting on a tip from an informer, Wilson ordered his police officers to dig near the chief's house, where they found the remains of 13 victims. The chief was put in prison to await trial, and Wilson set out on a determined mission to put an end to the leopard men's reign of terror.
But the local inhabitants were too terrified of the leopard cult to come forward. There were several more murders during the weeks that followed, including the wife and daughter of Nagogo, the imprisoned chieftain. A desperate Wilson hoped that the sight of the mutilated bodies of his family would anger Nagogo into betraying the cult members who had so obviously turned on him, but the shock proved too much for the chief. When he saw the bloodied corpses of his wife and daughter and realized how viciously his fellow leopard men had betrayed him, he collapsed and died of heart failure.


Although Wilson received 200 additional police officers as reinforcements, the leopard men became increasingly bold in their nocturnal attacks. One night they even sacrificed a female victim inside the police compound and managed to get away without being seen. After that cruelly defiant gesture, the cult committed several murders in broad daylight. The native inhabitants of the region lost all confidence in the police and their ability to stop the slashings and killings of the powerful leopard men. Even some of Wilson's men began to believe that the cultists might truly have the ability to shapeshift into leopards and to fade unseen into the shadows.
One night in mid-August 1947, Wilson was awakened by the warning growl from his dog. When he rose to investigate, a four-foot-long, barbed arrow whistled by his head, narrowly missing him and embedding itself in the wall. The next morning at police headquarters, he learned that two of his officers had also barely escaped death that previous night.
Wilson knew that his men were becoming unnerved. They were trying to stop an enemy who was essentially invisible. They struck without warning after preselecting their victims by a process that evaded all attempts to define it. There was no way for Wilson and his officers to determine who the cult's next victims would be or to guess where they might strike. And the natives were far too intimidated to inform on the leopard men—if, in fact, they did know anything of importance to tell the officers.
The district officer decided to attempt to set a trap. On the path to a village where several slayings had already taken place, Wilson sent one of his best men, posing as the son of a native woman. The two walked side by side toward the village while Wilson and a dozen other officers concealed themselves in the bushes at the side of the path.
Suddenly, issuing the blood-curdling shriek of an attacking leopard, a tall man in leopard robes charged headlong at the couple, swinging a large club. The young police officer struggled with the leopard man, but before Wilson and the other men could arrive on the scene, the cultist had smashed in the officer's skull with the club and fled into the bushes.
Wilson had lost one of his best officers, but the knife that the young man still held in his hand was covered in blood. The police would now be able to search for a man with a severe knife wound.
The district officer was about to have some men take the constable's body to the compound when he had a sudden flash of intuition that the leopard man might return to the scene of the crime. While the other officers searched the neighboring villages, Wilson hid himself behind some bushes overlooking the trail.
Around midnight, just as Wilson was beginning to think about returning to the compound, a nightmarish figure crawling on all fours emerged from the jungle, pounced on the young officer's corpse, and began clawing at his face like a leopard. But rather than claws raking the body, Wilson caught the glint of a two-pronged steel claw in the moonlight. The killer had returned to complete the cult ritual of sacrifice. Wilson advanced on the leopard man, and the robed murderer snarled at him as if he were truly a big cat. When he came at him with the two-pronged claw, Wilson shot him in the chest.
With Wilson's act of courage, the natives of the region had been provided with proof that the leopard men were not supernatural beings that could not be stopped. The members of the cult did not have magic that could make them impervious to bullets. They were, after all, men of flesh and blood—savage, bestial, and vicious—but men, nonetheless. Once word had spread that the district officer had killed one of the leopard men, witnesses began to come forward in great numbers with clues to the identity of cult members and the possible location of a secret jungle shrine.
The shrine itself was discovered deep in the jungle, cunningly hidden and protected by a large boulder. The cult's altar was a flat stone slab that was covered with dark bloodstains. Human bones were strewn over the ground. A grotesque effigy of a half-leopard, half-man towered above the gory altar.
During February of 1948, 73 initiated members of the cult were arrested and sent to prison. Eventually, 39 of them were sentenced to death and hanged in Abak Prison, their executions witnessed by a number of local tribal chiefs who could testify to their villages that the leopard men were not immortal.
Interestingly, on January 10, 1948, just a month before the leopard men were hanged in Nigeria, three women and four men were executed for their part in the lion men murders in the Singida district in Tanganyika. The lion people had dressed in lion skins and murdered more than 40 natives in ritual slayings that left wounds on their victims that resembled the marks of a lion's claws.       
(I stole that article from http://www.unexplainedstuff.com )