Most pattern mutations in the Cornsnake are simple traits, inherited in typical Mendelian recessive fashion.  In at least two cases, the traits are involved with each other in some way, although the mechanism is not fully understood.  Combining pattern mutations with color mutations can lead to some exceptional looking specimens indeed.  Since pattern mutations essentially affect the distribution of the pigments, many specimens appear much brighter or cleaner than typically patterned individuals of the same color morph.

Motley
This, the first recessive pattern trait discovered in cornsnakes, is also one of the most complex.  The mechanisms involved in the redistribution of pattern are not understood at all.  However, a few plausible theories have been postulated.  The motley pattern affects the entire animal.  Belly patterning is completely absent.  In most examples there is a complete dark line along the edge of the ventral scales, matching in coloration what one would suppose the ventral checkering to be.  The supposition is that the ventral patterning has been aligned along the edges of the ventral scales.  Lateral pattern is either absent or has been reduced to faint irregular striping along the lower sides.  The dorsal pattern may consist of either widely spaced elongated blotches, often fused at the sides to form a ladder pattern, or nearly full-length parallel stripes.  Extremely variable, leading to several named variations such as Q-Tipped, Pin-Striped, and Hurricane.

It is known that the motley and stripe allele share the same locus, yet the Motley appearance is dominant to that of Striped. Thus specimens with two motley alleles appear motley patterned, those with two striped alleles appear striped and those with one of each allele appear Motley, but are heterozygous for Stripe.

Striped
Two nearly perfect full-length dark stripes surround a full-length light mid-dorsal stripe.  Lateral pattern is largely reduced to fain irregular stripes or elongated blotches.  Often the pattern of stripes is broken near the vent and onto the tail.  As in the motley pattern variant, ventral pattern is absent.  Consistency of striping is extremely variable, with some specimens appearing more blotched than striped. This has led to a variety of named appearances - none of which seem to breed true in a consistent fashion. Among these are Cubed, Patternless and Vanishing Stripe.

It is known that the motley and stripe allele share the same locus, yet the Motley appearance is dominant to that of Striped. Thus specimens with two motley alleles appear motley patterned, those with two striped alleles appear striped and those with one of each allele appear Motley, but are heterozygous for Stripe.

Zigzag or Zipper
Appears to be caused by a longitudinal misalignment of the two (left and right) halves of the dorsal pattern blotches.  The result erratic combinations often form a broken pattern resembling a thick wavy line down the dorsum.  A Zigzag or Zipper, if you will.  Although the trait is a simple recessive, specimens which are known homozygous for the trait occasionally fail to exhibit it visually.  In actuality, it just happens that the misalignment of the two may be re-aligned by chance - and the result appears completely normal to our eyes.  Most examples of this mutation have areas which appear completely normal due to this.  Recently, breeders have concentrated on this trait and have 'enhanced' it into more and more severe pattern deformations.  As they are stabilized genetically, many are given new trade names.  Aztec is one we hear a lot.

Plain-Belly
A total lack of ventral pattern is found in another cornsnake color mutation.  The early examples of the 'Blood-Red' morph lacked all traces of ventral patterns.  It has been demonstrated that this trait is inherited separately from the blood-red trait, and can be passed to other color mutations.  It has also been conclusively demonstrated that it is genetically distinct from the lack of ventral pattern exhibited by motley and striped cornsnakes.  Unlike those two pattern morphs, there is no tendency for dark striping along the edges of the ventral scales, indicting a change in distribution of ventral pigments.  Rather, all pigmentation is simply missing.

Banded
The genetic origins of this trait are unclear, and it may in fact be a simple variant of the motley trait.  However, it is distinct enough in appearance to be discussed here.  The dorsal blotches are simply expanded down onto the lateral regions to give the appearance of a banded snake, rather than blotched.  The best specimens also appear to lack the intermediate lateral markings.  As this trait is fairly new to the scene, it remains to be seen where it will lead.

Frosted
Appears to be a pattern trait in which pigmentation is concentrated at the center of each scale, producing a pale speckled look.  Has been crossed to several color mutations.  This trait can be seen to a degree in many cornsnakes, but specimens which have been selected for this tendency are very unique in appearance.  Here's another relatively new genetic trait for breeders to explore.

Wide-Stripe
A very new cornsnake pattern variation, not yet fully understood. It appears as a very wide mid-dorsal stripe, with slight wavy edges. Side patterns tend to be reduced to thin vertical bars on many specimens. Mode of inheritance is uncertain at this point, but our limited breeding results indicate this is may be a dominant mutation. Thus far, all of our breedings between two wide-stripes have yielded 100% wide-stripes. Breedings between wide-stripes and unrelated anery and snow specimens have also yielded 100% wide-stripes. Currently very few specimens exist.

Piebald
Generally termed 'Calico' in the trade, although there may in fact be two or more mutations present in captive collections which fall under this label.  The first discovered incidence of piebaldism involves animals which develop varying amounts of white scattered patches during later years of life.  These patches are associated with some form of cellular disruption appearing as blistered deformities of the scales.  Breeders are currently attempting to see if this negative trait can be separated from the 'desirable' one.  

A few recent hatchlings have appeared to be true piebald specimens, in which large areas are devoid of pigment at birth.  Future breeding projects will determine if this trait is genetically inheritable or simply a developmental anomaly.  The parallel trait in the Ball Python (Python regius) was proven inheritable in the summer of 1999...