Voodoo doll

The voodoo doll appears in The Sims: Livin' Large, as a reward for visiting a hidden lot in The Sims 2: Bon Voyage and as Premium Content in The Sims 3 Store. The voodoo doll returns in The Sims 4 as seen in the gameplay trailer.

The Sims: Livin' Large
The voodoo doll was introduced in The Sims: Livin' Large and was available in buy mode. The doll can be used to torment Sims. When used on a Sim, the Sim's comfort and fun motive will drastically decrease. If the victim is in the same room as the Sim using the doll, they may slap them, and relationship will decrease. The doll will not be used autonomously.

The Sims 2: Bon Voyage
The voodoo doll returned in The Sims 2: Bon Voyage as an object only obtainable while on vacation.

The doll can be used to perform various activities, from useful things such as making friends or falling in love with another Sim, or more annoying things such as making a Sim hotter or colder. The doll may fail and backfire on the user if used too often, and can be sold in Sim-owned stores, if frequent visits are made to the Witch Doctor for new supplies.

If a Sim wants the doll, they can acquire one from the witch doctor after repairing all of his broken appliances. As with other repairs, success depends on the Sim's mechanical skill. The witch doctor will lie in his hammock after being greeted, forever lying there until all of the appliances are repaired. Upon successful completion, he will give the Sim the doll as a gift. However, he will cancel the interaction if the Sim is still busy and won't accept the doll. This can be inconvenient for a Sim trying to get the doll, as that Sim may need to idle for a while before the Witch Doctor tries to give the doll again.

Five voodoo dolls may be collected on the souvenir shelf. If that is done, nearby Sims will be cursed into imagining they are being attacked by a bee swarm.

The Effects
The voodoo doll can perform these actions:

Warm up: If Seasons is installed, the victim's temperature will increase. Otherwise, his/her comfort motive will drop.

Cool down: If Seasons is installed, the victim's temperature will decrease. Otherwise, his/her comfort motive will drop.

Romance: Makes the victim fall in love with the user, and automatically queues up the "Make Out" action.

Friendship: Makes the victim become friends with the user.

Saturate: Drastically reduces the victim's bladder motive.

Stinkify: Drastically reduces the victim's hygiene motive

Shake Up: Reduces the victim's comfort motive, and may cause the victim to throw up.

Agitate: Drastically reduce victim's comfort motive.

The Sims 3
As of January 2012, the Malleable Mimic Voodoo Doll is available for purchase from The Sims 3 Store, for 600 SimPoints. In-game, it is available in Buy mode for §416, and can be used by Sims aged teen and older. It can be found in buy mode by clicking Sort by Function -> Entertainment -> Miscellaneous Entertainment, or Sort by Room -> Study -> Hobbies & Skills.

Using the voodoo doll excessively might result in Electrocution or "The Cupid’s Wrath"!

Uses

 * Bind To... and Change Bind To...: used to select which unsuspecting Sim is going to come under the voodoo doll's magic
 * Bless: gives the bound Sim the "Voodoo Blessing" positive moodlet, and makes the Sim’s life even better!
 * Curse: gives the bound Sim the "Voodoo Curse" negative moodlet which makes things a lot worse!
 * Wet Pants: makes the bound Sim's bladder need zero out and gives them the "Embarrassed" negative moodlet
 * Hot Foot: light's the bound Sim's toes ablaze and gives them the "Hot Foot" negative moodlet
 * Pins and Needles: pokes and prods the bound Sim with pins and needles, giving them the "Poked and Prodded" negative moodlet
 * Cupid's Arrow: makes the bound Sim fall head-over-heels for the player's Sim and gives them the "Smitten" positive moodlet

Trivia

 * In The Sims 2: Bon Voyage, the Witch Doctor is immune from the voodoo. The doll will always fail and backfire on the user if used against him. He will laugh at the user after that.