Procreation

Monsters and humans procreate in different ways. For human procreation, look that up yourself; the internet would be happy to tell you.

## Monster Reproduction

Monsters reproduce through a process where fragments of magic merge to create a baby monster with genetic traits being passed along through a magical process [38]. This can happen regardless of monster type or gender, though the process of same-sex pregnancies was developed over years of experimentation [7].

For monsters, biological reproduction is a spectrum. There's the standard capabilities associated with women and those associated with men, but more variation exists. Some monsters are fully hermaphroditic, capable of impregnating others and becoming pregnant themselves. Some can reproduce asexually, while others have the option of doing this or reproducing with a partner [50].

When having sex, if a monster is passionate towards their partner, they can inadvertently cast the procreation spell and thus cause an accidental pregnancy. Conversely, a one-night stand is far less likely to produce a child [39]. Accidental pregnancies are rare among same-sex couples [7]. Further, the difficulty of creating a child increases if more than two monsters contribute to its conception [16]. Contraceptives exist for monsters, but while highly effective, do not drop the chance of pregnancy to zero [39]. These can vary from magic-based pills to condoms similar to what humans have, though in some cases, ones designed for humans can also work [47]. Due to difficulty some monsters have with casting certain spells, infertility can still be a problem with monsters [40]. Further, magical equivalents of STDs and STIs exist, and can be passed making sex among monsters no less hazardous than sex among humans [43].

The child's magical talent cannot be accurately by the abilities of the parents alone, so training the child is more effective in creating a prodigy than selective breeding [28].

## Pregnancy

most monsters can spontaneously generate a womb, but a boss monster's reproductive system is similar enough to a human's that they cannot [15]. If the womb is unable to be generated, the child is grown inside an egg or a bubble of magical energy [5], but if two male monsters want to have a child, they must combine magic-fragments in a special container and then brought to a female monster to incubate provided neither of the monsters can change their parts around to make it work [8]. Abilities that one monster had may be passed onto the child [3].

Pregnancy lengths range from the longest with the tortoise monsters which can last decades to slimes, who can asexually reproduce in 10 minutes [22]. Beast monsters generally have pregnancy last the same length as the animal they resemble, but those who are a mix of species generally have the duration of pregnancy between the two species. For example, elephants monsters have a fairly long gestation period, while kangaroo monsters have it much shorter. If the offspring of these two species were to get pregnant the pregnancy would last somewhere between what their parents' species would have to endure. Of course, any of these monsters' siblings might a different duration entirely [48].

Just like with humans, monsters can have accidental pregnancies [24].

**Bubble:** When it comes time for the child to be born, the mother becomes lethargic and feels an overwhelming urge to lie down, and the bubble will pop while they're resting [21]. Artificially popping the bubble acts like being born prematurely [25]. The bubble can be transferred to another monster in some cases, but the magic involved is complicated [26]. A boss monster that reproduces with a non-boss monster has a 50% chance of creating a boss monster with new traits and a 50% chance of creating a regular monster [14] [2].

**Egg:**  Eggs are still made of magic and if destroyed will turn to dust [32]. Should a wizard be born from an egg, they appear as if they had been incubated in a womb [30]. An laying an egg is less painful than natural childbirth [35].

### Exceptions

A ghost that has possessed an object is only able to pass on traits related to their body, not ghost traits [16].

Slimes reproduce with other slimes by fusing into one being [23].

### Human-Monster Procreation

Most monsters have the right parts for making a child with a human, and those that don't can make them with magic [18]. In order for a human and a monster to have a child, the monster must create DNA to fuse with the human's [38]. It follows the same process as human reproduction plus a spark of magic. It is theorized that a human and a monster could reproduce with the human substituting Determination for magic [1] [9].

The exact procedure for how a wizard or boss monster child is chosen to be formed, is as follows. Upon encountering each other, human genetic material and the procreation spell interact with each other in a sort of wrestling match where the stronger forces the other to become like it with either the human cell(s) forcing the magic to become genetic material and form a wizard zygote or the magic converting the cell(s) into more magic and forming a boss monster. That said, there is precious little research on this subject [44].

A human-boss monster union would produce a child with an incredibly powerful soul [4]. Currently, no one, save for those monsters still alive from before the war, such as Gerson, know how this process would work [9]. A human and monster can still have an accidental pregnancy as described above given that a monster's magic works on emotions [39].

A human and a monster reproducing are most likely to get a wizard child, though a young boss monster is an option as well [13]. The wizard will inherit some traits from their monster parent, but will still appear outwardly human [31]. It is possible for a wizard and a boss monster to be born as fraternal twins [45].

Should a ghost attempt to make a human embryo into their body, the result would be a miscarriage or if the ghost's timing is off, the baby's soul will appear and fight the ghost off [37].

## Inheritance

The exact process of how traits are inherited for monsters is not very well understood and is substantially different from human genetics [42]. Among monsters, appearance is shaped by nature, while personality, actions, and preferences are primarily shaped by nurture [33]. Further if a monster was previously a poltergeist or a dust lich, their traits from this time can be passed on to future offspring even if they have regained their previous form [41].

### Monster-Monster

These are the official chances of what a monster might be born as given its parents [17]. Types are listed here.

* **52%** A child with a blend of their parents traits and types. In the case of two elementals, their elements are combined [29].

* **32%** A child with only one of their parents traits and type.

* **14%** A child with one of their parent’s type and trait and and the other parents type but not their trait.

* **1.89%** A child with one of their parent’s type and trait and not any of the other parent’s type(s) or trait and one other type that neither parent has.

* **.049%** A child with only one of their parents types but none of either parent’s traits.

* **.06%** A child with both of their parent’s types but none of either parents traits.

* **.001%** A child with a type that neither parent has.

The .001% chance is the chaotic nature of magic rather than a category error. There is usually a form of logic to what results, but is never consistent between also cases, for example, two ape monsters having a child that looks like homo erectus because "they evolved" [49].

### Wizard-Monster

These are the official chances of what the child of a wizard and monster would be [19].

* **75%** Boss Monster
* **25%** Wizard

### Wizard-Human

These are the official chances of what the child of a wizard and a human would be. [20]

* **50%** Human
* **50%** Wizard

### Monster-Human

The magic particles of a monster that procreates with a human will remodel themselves after human chromosomes in order to reproduce [36].

These are the official chances of what the child of a monster and a human would be.

* **50%** Wizard
* **50%** Boss Monster

### Boss Monster-Human

These are the official chances of what the child of a boss monster and a human would be.

* **75%** Wizard
* **25%** Boss Monster

### Monster-Boss Monster

These are the official chances of what the child of a monster and boss monster would be.

* **50%** Monster
* **50%** Boss Monster

### Ghost With a Body-Monster

These are the official chances of what the child of ghost that has acquired a body and a normal monster would be [27]. This entry uses Mettaton and Papyrus as an example.

* **25%** Ghost
* **25%** Robot or Skeleton
* **50%** Combination of Ghost, Robot, and/or Skeleton

Sometimes the chance of a monster being born a ghost can skip a generation and result a later descendant being a ghost. The odds of a child being born a ghost increase if both parents are or were ghosts [34].

### Wizard-Boss Monster

* **50%** Wizard [14]
* **50%** Boss Monster

## Unions

* **Moragore Dreemurr**(male goat boss monster) and **Ascylla Dreemurr** (female goat boss monster) had **Asgore Dreemurr**(male goat boss monster). **Manuel**(male goat boss monster) and **Victoria**(female goat boss monster) had **Toriel**(female goat boss monster). **Asgore Dreemurr** and **Toriel** had **Asriel Dreemurr** (male goat boss monster). In these cases, each set of parents were goat boss monsters and as result the children were goat boss monsters as well.
* **Alphonse**(male triceratops monster) and **Axel**(male chameleon monster) had **Alphys**(female lizard monster). Alphonse and Axel were similar enough to each other appearance-wise that **Alphys**  didn't look drastically different from either of them. Alphonse's race is capable of changing gender [10], so a surrogate was not needed to lay Alphys's egg [11].
* **Mrs. Monster**(female tyrannosaurus (?) monster) and **Mr. Monster**(male monster) had **Monster Kid**(male monster). Monster Kid seems to favor his mother, the majority of his features seeming to come from her, but he has his father's eye shape and stripes in his skin color going down his body.
* **W.D. Gaster**(male skeleton) and **A.R. Hermann** (female skeleton) had **Sans**(male skeleton) and **Papyrus**(male skeleton). Again, the parents were the same species, so the children would be the same.
* **Freja**(female mermaid) and **Valorie**(female shark monster) had **Undyne**(female fish monster). Undyne is the most drastic example. She has Freja's upper torso and Valorie's legs. Her and teeth are Valorie's, and she lost Freja's ears. She seems to have inherited Freja's combat skills, and Valorie's musical talent. Freja was the one who laid Undyne's egg [12].

## Trivia

* Undead monsters still suffer the effects of living pregnancy [6].

## References

[2] http://askfriskandcompany.tumblr.com/post/141801684707/all-this-talk-about-boss-monster-breeding-led-me
[3] http://askfriskandcompany.tumblr.com/post/141802588747/hm-so-like-with-the-dragon-decended-boss
[4] http://askfriskandcompany.tumblr.com/post/141802658182/how-strong-would-the-soul-of-the-child-of-a-human
[5] http://askfriskandcompany.tumblr.com/post/141814989337/so-about-the-monster-baby-things-where-is-the
[6] http://askfriskandcompany.tumblr.com/post/141851397157/if-a-skeleton-was-pregnant-would-it-experience-all
[7] https://askfriskandcompany.tumblr.com/post/142230235957/so-wait-if-monsters-can-do-the-baby-thing
[8] https://askfriskandcompany.tumblr.com/post/648540199721353216/im-not-sure-if-you-already-explained-how-but-in
[9] http://askfriskandcompany.tumblr.com/post/142405759727/would-human-monster-hybrids-be-expected-here
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[11] http://askfriskandcompany.tumblr.com/post/144082710552/also-from-sans-lecture-but-in-the-case-of-two
[12] http://askfriskandcompany.tumblr.com/post/144114847447/so-which-one-laid-undynes-egg
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