Programmer Art

The things to keep in mind with 3d characters is their interaction with their environment and other characters standing by. If they were real characters there would be no problems at all. However in game worlds the awareness  and interaction between things is stripped down to the rules the programmers  write. Thus, although you have a model of a dragon, it is effectively blind deaf and dumb and completely oblivious to the perils and activity around it  and either stiff as a board alternately gliding though things like a ghost and  bumping into things like a plank(things also seemingly invisible).

Unless the programmers allow it.

What does it have to do with design?

Well the problems that arise are often when you put big things next to little, or long things like tails, or awkward things like winds, or turning big things or putting big things on slopes.

Or putting big things with tails and wings on slopes turning in a crowd of little things.

Or when big things with tails and wings fall over dead.

Or when big things need to navigate narrow turning passages or bottlenecks where the AI of game leads a lot of characters to navigate (choke points).  In computer games they may possibly be called choke points because the player has a sudden urge to choke the designer or the programmer responsible when their characters  or units are stuck in a traffic jam and getting annihilated by the enemy.

so before you go nuts drawing cool things with long tails and wings you often need the approval of programmers- but often you were drawing these things for a game designer.  So either the programmer is excited about something neat finally getting into the game or you have to get them to sit down first and maybe promise that someone a lot better looking than yourself might rub their feet or something in gratitude.

The things programmers might use to figure out how bit things are when they need to bump into things or not fall through things, or interact  are a large quick initial guess say like a forcefield like sphere and a simpler version of the character thats invisible that moves with the character called a collision mesh or collision volume. The collision mesh is attached to the skeleton like the skin of the character so it moves with it. Basically the more inefficient these simple versions are at describing the space a character takes up the more difficulties the character might have navigating and interacting. Collision meshes also don't like concave forms very much.