Ilomba is a sea snake with destructive powers in the mythology of the Lozi people of Zambia. It is provided by a witch doctor. Usually it is fed with eggs and porridge in the morning. It takes on the identity of the person that owns it. If it is killed, the owner feels the pain, and then dies. If the owner dies, it dies. The only way it can be destroyed is through the witch doctor.

~wikipedia

 It appears as a regular seasnake to normal people but on the desired target it has the head of it’s creator. …The eyes of the Ilomba paralyses the victim with fear and bites it sucking the blood and devouring its soul that makes the Ilomba double in size. The sorcerer or witchdoctor collects these souls to use as zombies.

http://fuckyeahafricanmythology.tumblr.com

The ilomba comes from Zambia, but is known here and there throughout Africa. It looks like a normal snake to most people. Only its victim sees its true nature. It’s made by a sorceror, whose face it will have when it attacks. It not only sucks the blood from its victim, but also their soul.

In this image a woman walks through a group of snakes, one of which is the ilomba. The fact that snakes are common in Zambia makes this tale all the more frightening- at any time you could be right next to one of these creatures and not even know it. Like many other monsters in mythology, it hides in plain sight. The ilomba may be created by a sorceror, but it is not ruled by one. The person who makes an ilomba must feed it, by directing it to other people to devour them. Without blood or souls, the ilomba turns on its creator, killing them both. And if an Ilomba is killed, its creator also dies.

(All this and more about the ilomba, in my book!)