Polymorph

In general, a polymorph is something that can exist in several states or forms.

A polymorph can be:

In biology, Dreissena polymorpha is the scientific name for the Zebra mussel.
In materials science, a polymorph is a solid which shares chemical composition with another material but is composed of a different crystal lattice or form, see polymorphism (materials science). Also see allotropy.
In algebra, a polymorph is an integer which can be expressed in multiple ways using a certain form (further explanation at mathworld.wolfram.com).
In fantasy role-playing games, polymorph means to change the shape of something, usually from one living being to another, and usually via magical means.
A Polymorph was also a character in the British science fiction sitcom Red Dwarf.

You may also wish to check the disambiguation page for polymorphism.