Who are zombies

Hi to all please let me know who are zombies and how they become.

1.)Originally, a snake-deity of or deriving from West Africa and Haiti.

2.)A soulless corpse said to be revived by witchcraft, esp. in certain African and Caribbean religions.

Also known as a supernatural power that may enter or reanimate a dead body.

They look like a corpse would, but possessed. They aren't the friendliest of creatures either.......

A human corpse that has been demolished by a desiese making the no longer humanly functioning brain want other humans.