Mutations

Generally speaking, a mutation is a change in a horse's genetics, often one that is unexpected. In Horse Isle 3, the word "mutation" has come to refer specifically to somatic mutations, which are non-inheritable (non-genetic) markings that may appear on an equine if certain conditions are met.

There are seven somatic mutations in Horse Isle 3: Bend Or (Grease), Netting (Lacing), Flash, Bleach, Birdcatcher, Mosaic, and Tetrarch.

## Bend Or (Grease Spots)

Bend-Or Spots, most commonly known as "grease," are described as:

> darker pigmentation, ranging in red to black, typically found on palominos, chestnuts, and even darker colored horses. In Horse Isle, these spots can extend all the way to the neck- or be so small it's a little hard to see, being just a few spots on the rump.
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Grease spots are visually based on the 'holes' in appaloosa patterns (an inverse appaloosa).

### Requirements

Grease can be found on any horse, donkey, or hybrid that does **not** have an appaloosa coat.

Extensive grease on a bay coat.Extensive grease on a cream coat.Moderate grease on a sooty pearl coat.Moderate grease on a grulla coat.
## Netting (Lacing)

Netting, more commonly known as "lacing", is described as:

> a giraffe-like, reticulated pattern that appears on the backs of horses. It varies from just a bit along the topline or extending further down the horse's sides. Netting always consists of white hairs.
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Lacing begins to show between two and four years old, and will continue to grow as the horse gets older. The presence of roan or grey will cause the lace to age more rapidly and show more strongly. It will affect the natural mane of a horse.

### Requirements

Lacing can be found only on horses, donkeys, or hybrids that have the dapple trait. Dapples do not need to be expressed on the coat for lace to show.

## Flash

Flash is a white marking described as:

> This shocking white marking appears as white "lightning strikes" or swirls on any horse color, typically around the neck but it has been known to pop up on other areas, like the barrel or rump!
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Flash can vary in how extensive it is and whether it appears on one or both sides of a horse.

### Requirements

Flash can be found on horses, donkeys, mules, and zebras. Horses must carry at least one of the pinto genes, or the Lp allele, or have loud markings such as stockings or a wide blaze. Donkeys, hybrids, and zebras do not have these requirements.

## Bleach

Bleach markings are described as:

> a lightening of the coat, making the horse appear to have been 'bleached,' giving the horse grey spots with colored rims.
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Bleach spots can vary greatly in size, shape, amount, and placement. Their 'rim' will appear more grey than the rest of the spot, and can be seen as a foal. As the horse ages, the bleach spot will go through the greying process, eventually turning fully white by about age 15. This greying process will go faster if the horse is grey, or if the horse has roan (although the process will only be sped up in bleach spots where the roan also overlaps). Like regular grey horses, bleach marks can also become fleabitten. Fleabitten appears to show in bleach between age 14 and 14.4 when other greying factors are not present.

### Requirements

Bleach can be found on horses, hybrids, and zebras. A horse or mule must carry at least one of the pinto genes and have white markings (preferably on both legs and face). Zebras do not have this requirement.

### Black Bleach

A unique phenomenon found **only** in mules is the "black bleach". Caused by the hidden tyger gene trait, which creates a roaned overlay in spotted patterns on mules, black bleach is a regular bleach marking which has been "duplicated" on both the roan layer and the base layer of the coat. As a result, the base coat layer of the bleach goes from grey to black, instead of grey to white; the roan layer will go from grey to white as usual. This has been confirmed by the game staff to be a bug, but has been left in the game for collectors to enjoy.

## Birdcatcher

Birdcatcher spots are described as:

> white flecks or marks on an otherwise dark body, ranging in size from a few single white hairs to make the horse look like they're covered in ping-pong balls!
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Birdcatcher markings always begin at the rear of a horse, and may continue all the way up to the face if extensive enough; they will reach from the back down the barrel, but will not extend into the lower legs. They range in size and shape, but are always irregular and bright white.

### Requirements

Birdcatcher can be found on horses, hybrids, and zebras. Horses must carry at least one of the pinto genes, or the Lp allele, or have loud markings such as stockings or a wide blaze. Zebras do not have these requirements.

An example of extensive birdcatcher.An example of minimal birdcatcher.An example of minimal birdcatcher.
## Mosaic

Mosaic (called "mosi" for short by the community) is a strong color mutation described as:

> These large patches of color really make a horse stand out. It can be darker than the rest of the coat or lighter and the difference between the color patches is stark, not blended.
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Mosaic is an overlay of a base color over the rest of the coat of the horse, covering it in sections. The base color is chosen from a different shade of the same base color the horse is (ex: isabella palomino on copper palomino), or in cases of black-based horses, a brown shade (ex: sepia brown on sable black). The shade is chosen at random and may be lighter or darker than the horse's base coat.

White markings and patterns, brindle, lace, birdcatcher, flash, tetrarch, and bleach will lay on top of the mosaic instead of underneath it. Sooty, linebacked, mealy, and primitive markings will lay below the mosaic instead and be hidden by it.

### Mosaic Patterns

Mosaic has four fixed patterns the community has named "scarf", "sweater", "blanket", and "extensive":

* **Scarf** pattern has two sections. The largest section drapes across the withers, from the lower left flank around the right shoulder and ending in the middle of the chest. A smaller section winds around the right rear leg, from the gaskin down to the hoof.
* **Sweater** pattern has only one section, going from the middle of the barrel to the chest, covering from wither to hoof, with a half-swirl on the chest.
* **Blanket** pattern (sometimes also called "pants") has three sections. The largest section stretches across the hindquarters on both sides, up through the middle of the back. The second largest section runs down the left neck, from the crest to shoulder. The final, small section appears as a small patch on the right forearm of the horse.
* **Extensive** pattern has three sections. The first large section stretches across the hindquarters on both sides like blanket, and continues down the left rear leg to the hoof. The second section wraps around the withers, neck, and chest, as well as the right front leg. The final section forms a "bonnet" by wrapping around the ears and throat latch.

### Requirements

Horses, donkeys, and hybrids can be mosaic, making zebra the only equine that cannot be mosaic. The rules for an equine to be mosaic are extensive and cannot be on some coat colors, gene combinations, or breeds. A pinned forum thread goes over what breeds are, and are not, available in mosaic.

* **Color limitations:** The following coat colors are unable to be mosaic:
	+ Dominant white (W)
	+ Homozygous cream (CC)
	+ Homozygous (ChCh) champagne
	+ Red, bay, or brown-based Dun
* **Gene limitations:** Horses that are both grey and have rabicano cannot be mosaic. Additionally, the presence of sooty, roan, and rabicano genes reduces the chances of a horse being mosaic.
* **White markings:** Horses must have white markings (face and/or legs) to be mosaic. The exact measurable amount is unknown, and cannot be determined by simply looking at a horse. Player theories exist promoting paying attention to "Marking Amount" penalties against breeds like Agaba Dark Horse, Dales Pony, and Posavac to maximize white markings for breeding mosaics.

Special exceptions to these rules exist in specific cases:

* Dominant White ("White") donkeys can be mosaic, due a bug that has been intentionally left in the game. "Albino White" donkeys cannot be mosaic.
* While most dun horses cannot be mosaic, seal-brown and black dun (grulla) horses can be. This includes coats with dilutions in addition, such as classic champagne dun or silvery grulla.
* Donkeys and hybrids are not limited to grulla mosaics, and can have red, bay, and brown-based dun mosaics.
* Donkeys and mules do not require visible white markings to be mosaic.
* All donkey colors (except Albino White) can be mosaic and come in greater combinations than horses.
* Dominant black horses, and black-based horses (grulla, smoky black, classic champagne) with the dominant black gene, can roll a black-colored mosaic.
* Sooty mosaics can only exist on certain bases: chestnut, palomino, black, grulla, and silvery grulla. Sooty grullas can only be mosaic if they are not dappled. Bay, brown, and seal-brown based coats cannot be sooty and mosaic (this includes colors like buckskin).
* Mosaics with grey can result in a variety of different looks. Homozygous Grey (GG) horses will fully grey out, hiding the mosaic entirely, by age 5. Heterozygous grey (Gg) horses will grey out more slowly, but the mosaic portion of the coat will remain brighter or grey slower than the rest. If the grey becomes fleabitten, it will affect the mosaic area as well as the base coat, resulting in a stark difference with black and red/brown flea spots.

## Tetrarch

Tetrarch (called "tet" for short by the community) is described as:

> white spots on a grey coat, named for the grey Thoroughbred stallion that made them so well known and passed the mark on to his descendants.
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Tetrarch spots are based on the holes in appaloosa patterns (an "inverse appaloosa") and vary greatly in extensiveness and pattern. These spots *typically* start around the lower leg and move up the hindquarters before reaching the face and barrel; however, instances where there are no leg markings present have occurred. Unlike birdcatcher, tetrarch spots are not bright white, but tend to be translucent (although they will appear a stronger white as the horse ages).

### Requirements

Tetrarch can only appear on horses or mules with grey (either heterozygous or homozygous). It must also be 'll' for Leopard (carries no leopard gene) and have white markings. The white marking threshold for tetrarch is lower than it is for mosaic.

An example of tetrarch.An example of tetrarch.An example of tetrarch.An example of tetrarch.
## Additional Notes

Horses may have multiple types of mutation at once, such as having grease and mosaic, or lace and tetrarch. However, they cannot have two of the same mutation, such as two types of mosaics.

There is some confusion about certain markings and whether or not they are a mutation. As confirmed by game staff, "airbrush", badger, brindle, belton, fleabitten grey, and "static" pintaloosa are **not** considered mutations.