Traits

Tails based on mythical creatures or made up design that don't utilize actual animal tails.

Ornamental wings that do not function for flight. Often small or chibi in style.

Growths that consume parts of the body entirely (a half mushroom face, crystalized limbs etc).

A tail that splits into two.

Multiple pupils in the eye.

Shorter anatomical stature, often most noticable in the anatomy of the limbs and/or the torso.

Ears of unique shapes not seen in animals naturally.

A body/coat not belonging to a living creaure (cystal body, rock body, glass body, fabric body, etc).

No eyes / empty sockets (effectively blind).

Freely shaped pupils not animal in nature (shapes, mythical pupils, missing pupils, unique pupils etc).

A body that glows in its entirety in any way.

Feathered wings, bat wings, etc that grow from the back and are functional for flight.

Multiples of any limbs excluding tails.

Markings that move on the body, don't stay in one place, etc (these will often be gif designs).

Other strange mutations that do not match prexisting ones on our lists.

Any part of the body that changes shape or moves in abnormal ways (these will often be gif designs).

Resulting from a bite (event exclusive), date with a werewolf (exclusive) or very rarely passed down when breeding, lycanthropy causes the gorgi in question to shift into a monstrous, much more feral form when they lose control of their emotions, during a full moon, and on all howl's eve.

Two gorgis who are born physically connected to each other.

A foot that points down or turns in rather than normally. 

Claws from any species other than a canine, such as raptor claws or eagle claws.