As a Technical Artist responsible for the character-production, I mostly also created prototypes for all kinds of things before they go into real production. Depending on the asset, there can be several iterations where the mesh can still change a lot.
These are some of the character-prototypes for early gameplay- and animation- tests and also serve as a guideline for the final mesh- and texture setup.
To keep the prototype close to the final version, I used placeholder-textures to parts of the model and later projected the concept directly onto it.
After the concept is done, these prototypes were gameready in a very short amount of time while being very close to the final model.