Jakub in some versions is purely evil, in others he is well-intentioned but becomes evil.
This tale seems to have come from the mysterious founder of the Nation, Wallace Fard and was transmitted to Elijah Muhammad.
This is one of the tamer things they believe.
The Nuwaubians, the Ausar Auset and the Temple of Moorish Science are interesting too.
Sounds like a fusion of Islam and voodoo.