Your patron is one of the spirits or gods of the voodoo pantheon (Also refered to as an 'Iwa') such as Bondoye, the supreme god of voodoo. The iwa act as gods and spirits who grant mysterious powers that are linked to spirituality and nature. Most people call voodoo warlocks 'Witch Doctors', and they aren't seen in a good light. Many people do not understand voodoo and see it as another form of necromancy. However this is innacurate as most iwa tend to be neutral and witch doctors tend to be good. Your pact with an iwa also tends to lead you to listen to the spirits. In essence your pact is with an iwa but you will more often then not finding yourself serving the spirits as that alligns with what the awa seek to do.

Your paton could be Bondeye the supreme creator, Papa Legba the crossroad between the spirit world, Maman Brigitte the leader of the underworld, Baron Samedi the iwa of death, Erzulie the iwa of beauty and love, Ogun the warrior and blacksmith, Damballah the serpent, or Oshen of the water streams and sexuality.

Cursed Fetish

1st-level Voodoo Spirit feature

Your pact with your respective iwa has given you the choice to be granted a voodoo doll or a shrunken head. Depending on which one you chose you gain a different ability. Each object can can be used as an arcane focus, when this item is lost or destroyed you can spend a short rest to create a new one at the expense of not regaining your spell slots, and their abilities cannot be used by anyone that is not a warlock of your exact patron as well. You can change between the two after one long rest.

Shrunken Head

The Shrunken Head grants you a head of any humanoid race that has been shrunken using a medical process. With a bonus action you may attempt to attune to a target on the battlefield, they must pass your spell check DC or they are attuned to it for 1d12 minutes. If the target is killed while being attuned to it then the shrunken head acts as an extra spell slot. These extra spell slots can be collected however they go away at the next long rest or if it is lost or destroyed.

Voodoo Doll

The Voodoo Doll grants you a doll which you can attune to other people. With a bonus action you may attempt to attune to a target on the battlefield, they must pass your spell check DC or they are attuned to it for 1d12 minutes. While they are attuned to your voodoo doll you can hit the doll with an attack to do damage to the opponent. The doll shares the targets ac, however you get advantage against attacking the doll. When you hit the doll you do normal damage along with another D6 of necrotic damage. Every two levels this D6 is increased by another die. (Levels 3, 5, 7, 9, 11, 13, 15, 17, 19). You cannot destroy the doll if it is attuned to a target. 

Animate Shadow

6th-level Voodoo Spirit feature

Your Iwa gods give you the ability to animate your shadow which is always within' a five foot square from you. This shadow has your hit point maximum and your stats. The shadow attacks with your bonus action. On top of this you gain immunity to attacks that drain stats. You also gain resistance to necrotic damage. 

Strings of the Spirits

10th-level Voodoo Spirit feature

When you kill a creature you can then switch places with it's corpse before your turn ends, doing this will also grant you an extra action. This imposes no attack of opportunity from a target that may have been next to before teleporting.

Flesh to Leather and Fabric

14th-level Voodoo Spirit feature

Once per long rest if you attune your fetish to a creature you can destroy it to deal 5d10 necrotic damage to the attuned target. If this kills the target then they are turned into the same fetish you had and can only be brought back via the wish spell. If this fails to kill your target then you lose your fetish until the next long rest. This attack gains another d10 of damage every 2 levels. 16, 18, 20 levels.