Baby Face primarily takes the form of a laptop equipped with a trackball, in which there is a hole where Melone can insert a small bottle of sampled DNA. From the bottom of the computer protrudes a large face, and occasionally limbs. It is notable that Baby Face can be seen by ordinary people.
The homunculus it generates takes the form of a humanoid with no noteworthy features save for the crest of spikes on its head. Its midsection is composed of several cables attaching the two halves of its body. It begins with the proportions of a child, resembling an evil version of Echoes ACT3,[2] but it can experience "growth spurts" that give it a more mature appearance.
Baby Face and its spawn are both presented as being light blue in the colored manga and lavender in the anime adaptation. While Baby Face itself is not shown in the PS2 game, the homunculus is shown as being white with lime green spikes.
Personality
While Baby Face itself has no personality to speak of, the homunculus it generates is an independent Stand with separate sentience from its user. Since it is born with intellect but no knowledge, it requires proper education to ensure positive growth;otherwise, it will become disobedient and uncontrollable.
The homunculus's personality is based on its "mother" and shaped by Melone's "education" as it develops. The one used against Bruno Bucciarati's group had a hotheaded "mother" and demonstrated such personality traits.
Abilities
Baby Face
Baby Face's base entity is an automatic Stand with little combat ability, therefore it isn't suited for direct confrontation. Its strength resides in its ability to create secondary Stands for Melone to sic on a target. It is laborious to set up, but inherently very safe as a trade-off.
Homunculus Generation
Melone can create a specially tuned human-Stand hybrid
Through its computer Stand, Baby Face has the ability to generate a secondary Stand that will fight in its place.[3]
By researching a suitable subject through the pseudoscience of examining a woman's characteristics, Melone gathers information and predicts the future homunculus' predispositions. Some traits that are identified include the woman's age and health (used to determine the physical strength of their "child"), their blood type and horoscope (which determine their "compatibility" with Melone's target; a poor compatibility leads to an aggressive "child"), and their preferred sex positions from the Kama Sutra (the relevance of this is unknown).
If the data predicts a child suitable for his purposes, Melone unleashes Baby Face on the woman and impregnates her with Baby Face's child through undisclosed means.[4]
Though the child is progenated through undisclosed means, it is stated that the insemination holds no similarities to human reproduction; upon waking up post-Stand encounter, Baby Face's victim shows no signs of being raped.[2]
The development is fast, taking three minutes for a fertilized egg to fully develop into a new homunculus[4] that then appears near the host. The child also appears to develop within or around the mother's head, approximately towards the back. This is hinted at when Baby Face's speech seemingly originates from that point, and urine trickles down the target woman's neck when it relieves itself.
If Melone possesses a sample of a target's blood, he can incorporate it into the homunculus by placing the sample in a niche beside Baby Face's keyboard. The resulting homunculus will be able to sense the target's location and track them no matter the distance.[4]
Computer
In addition to generating homunculi, Baby Face can be used like a regular computer, capable of holding and interacting with the data gathered by Melone.[4] The computer Stand also maintains contact with the homunculus, as if Melone was having an online discussion with the homunculus' spirit. A webcam and microphone allow Melone to show the homunculus images and converse with it orally.[3] It also monitors the homunculus' status, allowing Melone to watch its growth.[5]
Homunculus
The secondary Stand (or homunculus) that Baby Face creates is an independent, long-range, power-type Stand that acts as a surrogate fighter for Melone. It is powerful by default, can develop further depending on the progenitor, and its demise doesn't affect Melone, making it useful as a proxy assassin.[6]
On the other hand, because of its independence, it can disobey its creator under duress. Its creation is also a lengthy and intensive process, as Melone must find a suitable "mother" and train the resulting homunculus in order to carry out its mission. As a unique mix of human and Stand, the homunculus can be seen by anyone[6] and is vulnerable to mundane things most Stands are immune to, like burning.[5]
Matter Manipulation
Bucciarati is turned into nondescript cubes
By generating a square-shaped vacuum, the secondary Stand is capable of breaking matter apart into cubes while keeping lifeforms alive.[3]
It can forcefully divide anything it touches into cubes, or merely extract a single cubic part of the target.[7][8]
Upon dicing something, Baby Face is capable of rearranging and reconstituting the structure of said objects into anything it desires; for instance, it separated Trish's body into cubes and rearranged them into a table. It can even apply its powers to itself, reproducing the appearance of anything and blending in with the environment.[7][8] The homunculus can thus hide inside an object, go into any adjacent object, or even fly about as a mass of cubes in order to evade attacks.[9]
Although cubed people typically stay alive despite their condition,[10] Baby Face can weaponize its ability by removing key parts of the body like the throat.[8] It can also absorb the cubes for nourishment, although it is only seen using this on its "mother" to hasten its growth.[3]
Physical Growth and Aging
The homunculus starts as a small baby able to hide inside someone's hair. Over a short period of time, it will grow both physically and mentally into a fully aged adult.[3]
Aside from developing physically, it will grow as a Stand itself. While most autonomous Stands, such as Killer Queen's Sheer Heart Attack, lack precision or the ability to allow their users a sense of awareness to their current condition and status, Baby Face is able to assimilate information witnessed or heard. Through that learning and Melone's counsel,[8] the Stand will become more powerful and efficient in combat. It can also acquire other skills separate from fighting, such as driving a motorcycle.[9]
On the other hand, it is free-spirited and may go berserk[6] and disobey Melone's orders, especially if its "mother" was strong-willed. For better or for worse, the Stand will then follow its instinct alone when battling an enemy.[5]