A spanking doll is a doll that is built to be spanked and to serve as a non-living artificial spankee. Such dolls are described in spanking fiction. For example, the science fiction spanking novel Melody's Stories mentions a 28th century spanking doll called Spanking Susie that is given to Penitatas to play with.
Any doll can be spanked (see children spanking dolls), but spanking dolls, by definition, are designed to be spanked. First, to be spanked by a human they must be big enough (up to life size). Second, they must have buttocks that are well-spankable (i.e. fleshy and impact-absorbing, not hard but also not too soft). Third, they are typically described as looking "spankable" (which often means attractive and/or cute) in their character design. High-end features could include sound (crying, begging), motion (squirming, kicking, etc.), artificial redness, and many other features.
Simple spanking dolls
Two examples of simple spanking dolls for children that were produced in the 1960s are Spank me, I cry (c. 1960) and Tickles (1963). As far as is known, to the present day no more realistic spanking doll and none for adult use has been built.
Spanking dolls could however find a future market, in particular for people who will like to enact child spanking without hurting a real child. Besides, 'mainstream' dolls that are much more lifelike than today's may also become popular as a general toy for children and adults in the near future.
Designing a spanking doll
Some attributes that are largely neglected in doll-making so far because of their technical complexity:
- Weight. Today's plastic and fabric dolls are unrealistically lightweight. A realistic weight would be approximately the weight of water of the same volume. To make handling the doll easier, its weight could be less than that, but not too lightweight.
- Bones. Humans have no exoskeleton like insects. We are bony inside and soft outside, whereas most of today's dolls are either soft throughout or hard outside.
- Flesh. Muscles are not like cotton wool or foam. They have weight and non-compressible volume - comparable perhaps to a gel-filled pad.
- Skin. Human skin is not like fabric or plastic - perhaps artificial skin could be made out of silicone or latex.
- Joints. In a realistic skeleton, the way the limbs can move and the limits of their movement are determined by the joints that connect the bones, and additionally limited by tendons.
- Temperature. A realistic doll would have human body temperature (37 °C (99 °F)), rather than room temperature like a corpse.
- Posing and motion. Decisions must be made regarding active vs. passive motion. Passive motion can come in two types: 'rigid' and 'floppy'. If active motion is implemented, it should involve all limbs including the torso.
- Speech. Realistic speech needs more than just sound: movement of the lips and lower jaw.
- Breath. Breathing (expansion and contraction of the ribcage) would make a doll appear much more alive. Voice could be coupled with breathing for more realism.
- Facial expressions. Will need complex muscle simulations.
- Reaction to stimuli. Will need sensors for touch, sound, pose, etc.
Spanking dolls vs. sex dolls
Some of the above mentioned life-like properties are already available in expensive sex dolls. These life-sized dolls are not designed for spanking but for sexual intercourse. Accourding to Wikipedia, "More expensive sex dolls ($600 to $7,000 or more) are made from silicone. They can be very lifelike, with face and body modelled on real women or men, with realistic skin material (similar to that used for movie special effects), with realistic (or real) hair. These dolls usually have an articulate PVC or metal skeleton with flexible joints that allows them to be positioned in a variety of positions for display and for sexual acts. Silicone sex dolls are obviously heavier than inflatable ones (which consist of mostly air), but are about half the weight of a real human of comparable size. They are made in the USA by Abyss Creations (the RealDoll), 1st-PC, Mimicon and others; and in Japan by Paper Moon, 4Woods, Orient Industries (the CandyGirl) and others."
Child-sized sex dolls are in some legislations considered  child pornography. This obviously applies only to sex dolls which have body openings designed for sexual intercourse, not for non-sexual life-like dolls.
The following excerpt by Lurking Dragon describes the Spanking Susie doll:
|“|| "The Spanking Susie (or Spanking Sam) doll was an important part of every convict's rehabilitation. It allowed them to resolve their complex feelings through appropriate age-play, both alone and with their peers. The wonderful toy was also very popular with other 'rejuves', as well as 'real' kids.
Melody's new doll was proportioned like a four or five year old, but sized relative to her own height, i.e. it was proportional to her as a five-year old would be to an adult. Tiny, proportional 'P's decorated its tiny hands. (It was the Penitatas version, of course). Its soft plastaflesh was very lifelike, particularly over the padded bottom. A spank or slap to that area would result in a lifelike flush of pink, shading to red with repetition. And Susie would respond with a large repertoire of appropriate sobbing and crying, begging and pleading:
"Waaaaaaah!", or "No! No Mommie! Susie be good!" or "Don't spank me! I be good!!". Pulling her little cotton panties away from her waist would result in a "Noo! Don't take my pannies down!" or "Not bare! Pleeze Mama! Not bare bottom!" Activating the doll while holding it upright would result in "I've been a baaad girl, Mama!" or even "I guess I need a good spankin', huh??" It was a wonderful way for rejuves (or real kids) to express their frustration about the external limits on their lives."
|— Melody's Xmas|
|“|| The idea behind the 'Spanking Susie' was that she was a perennial five year old. The doll was carefully chosen to match the size of her owner. She was built to be proportional to her 'Mommy'.
Let's say a normal woman is 1.7 meters tall, and Melody is 1.2 meters. And a normal, smallish five year old is about 107 cm. tall. So her new Spanking Susie doll is 75.5 cm tall — the height of a five year old IF Mel was a grown-up. As Melody grows up, each year her doll will 'grow' as well — but always remaining a five year old in size proportional to Melody.
Spanking Susies (and Spanking Sallys, the seven-year-old variant) were quite inexpensive, since so much of the dolls were recycled. Nevertheless, SpankKo made a profit on the original sales... But the real credits were in the yearly upgrades!
|— Melody's Xmas II|