Bonehilda

Boney is an NPC that was introduced in The Sims: Makin' Magic and later returned in The Sims 3: Supernatural.

The Sims: Makin' Magic
There are two versions of Boneyhilda(full name) in the game. One is the janitor on the Magic Town lots A Spooktacular Spot and Vernon's Vault. The other can be bought on residential lots as a magical (and much cheaper) equivalent of Servo. This version of Bonehilda is literally a "skeleton in the closet".

If the "skeleton maid" version of Boney is in her closet, clicking on the closet will give the "Knock" interaction. Selecting this will cause the selected Sim to go to the closet and knock on it, which will bring Boney out to do chores. The selected Sim does not have to have magic to do this.

While the "skeleton maid" version of Bonehilda is generally equivalent to Servo, there are significant differences:

Thing Boney dont do Servo doesn't
 * Feed a baby. Somehow, she manages to do this without waking the baby.
 * Bring in the newspaper.

Things Servo does that Boney doesn't
 * Garden.
 * Attempt to entertain visitors. In fact, non-magical visitors will freak out if they see Boney in action, and a hired maid will quit. A walking skeleton is one thing in Magic Town, and quite another in someone's home!
 * Serve food.

Misc. differences
 * Boney seems to place a higher priority on repairing. She'll probably repair a broken dishwasher or sink before trying to use it.
 * Players can send Boney back to her closet by clicking on her and selecting "Dismiss".

Boney also has a few quirks. If a bar is present, she'll take a drink before heading back to her closet. Naturally, the drink will flow through her and leave a puddle on the floor. If tombstones are present, she may wave to one of them before going back to her closet. She is also a fan of the Grim Reaper, and will try to get his autograph if he appears while she's out of her closet.

The Sims 3: Supernatural
Boneyhilda (full name) made a comeback in The Sims 3 in The Sims 3: Supernatural, where she plays a similar role to the one she had in Makin' Magic. She will act like a maid, keeping the lot clean and cooking meals. She will also act like a babysitter/pet-sitter, taking care of young Sims and pets, and even teaching pets some tricks. Should a fire start anywhere on the Lot, she will attempt to put it out. She stays inside the Boney Living Quarters, which can be bought in the alarms section of Buy mode, or the Miscellaneous area under Entertainment.

In order for Boney to do chores, a Sim must "Awaken Boney" at her living quarters. The Sim will wave a key, which causes her to come out. This is a remote action that can be performed anywhere on the lot. There are only two ways for Sims to interact with Boney: "Dismiss Boney" will allow her to go back to her living quarters, while "Chat with Boney" will allow a Sim to simply chat with her.

It seems she has been based on the Grim Reaper's coding, as aging her (via cheats) will result in a 100% black skin tone female Sim (with normal flesh and bones), just like the Grim Reaper's skin tone. She repairs broken objects and often gets electrocuted, which shows her as a singed figure. This can be fixed by sending her back into her coffin and re-summoning her.

Things Boney will do (she run tha house)

 * Prepare food. Although she won't serve the food to guests, she will prepare and stock the fridge with easy, normal-quality meals for Sims.
 * Clean. Pools of water, dirty cabinets and appliances, food left out in the open, burned carpeting, rake leaves, making beds, etc.
 * Repair. She will repair any broken appliance free of charge.
 * Put out fires. A capable firefighter, Boney will rush to extinguish a flame.
 * Chat. This counts as socializing. Loners are not disturbed, and Supernatural Fans get a bonus.
 * Work in groups. Boney's Living Quarters may be purchased and awoken multiple times.
 * Train dogs. In The Sims 3: Pets, Boneywill teach dogs tricks if she has nothing else to do. This makes her an easy way to have a trained dog.
 * Steal clothes. Oddly, she will steal the clothes of a skinny dipping Sim, causing them the embarrassed moodlet.
 * Drink. She will not only drink nectar if the bottle is open (leaving behind a puddle), but if a Sim tends a bar, she will stand at the counter and consume every drink available one after another. It's a good idea to dismiss her temporarily if the player plans on serving them at a party.
 * Protect. When a burglar is on the lot, she will immediately fight the burglar off, even without the burglar alarm.

Things Bonehilda will not do

 * Charge a fee. She will not stop working until Sims tell her to and won't ask for money. The cost of her structure does add to the bills, though.
 * Rest. Boney will never sleep and won't leave the lot or be distracted. If there is nothing for her to do, she will return to her living quarters and wait for the next job.
 * Laundry. In The Sims 3: Ambitions, Laundry is introduced and provides a great moodlet. Bonehilda will neither clean clothes, nor collect dirty clothes from the ground.
 * Build relationships. Although Sims may chat with Bonehilda, she cannot develop a friendship with a Sim.
 * Child care. Although she will attempt to interact with toddlers by holding them or giving them a bottle, it seems these interactions are broken and she will do neither. Boney is not a capable replacement for a babysitter.
 * Entertain. Boneyhilda will not entertain or socialize with guests.

Interactions with Sims

 * The Chat with  option will count as socializing.
 * While doing various activities, like watching TV on the sofa, Sims can ask Bonehilda to join. This will often start a chat.
 * Loners will not have the Enjoying Solitude moodlet disturbed by Bonehilda.
 * Cowards and the Neurotic will immediately flee the room if they see Bonehilda, even if they're also Brave.
 * Supernatural Fans will get a socialization bonus from Chat with Bonehilda.
 * Supernatural Skeptics will get a Scared moodlet from being in the same room as Bonehilda. This moodlet lasts 3 hours and detracts 25 points. Unlike a Coward or Neurotic, Sims will not flee the room and being Brave will protect them from the moodlet.
 * Toddlers and Children do not automatically fear Bonehilda, unless they are also Neurotic or a Coward. If they are, they will get Scared, but Toddlers will not flee the room.
 * Toddlers will sometimes be interacted with by Bonehilda, who will attempt to pick them up or give them a bottle. It seems like these interactions are broken, as she will do neither.
 * Babies are not interacted with by Bonehilda at all. Neurotic babies will not get the Scared moodlet.

Gallery
Bonehilda Brunehilde Kościlda