Reskinning mobs is good, but it can only go so far. Therefore, I propose a system where players can create their own mobs.
1) The author chooses whether the mob will be a fighter, frigate, cruiser, or battleship group. (dreadnoughts would be great too, but that's a whole `nother discussion)
2) The author will have some base stats, weapons, and abilities to start with*. The author can swap these out for other weapons/abilities**, and adjust its health and turn rate as well. The stuff equipped on the ship will determine whether the ship qualifies as weak, moderate, or powerful for its type (for example, a powerful battleship would be equivalent to a D'deridex). If it's too powerful, the author will not be able to enhance it further.
3) The author chooses a default skin for the ship (or more than one, like with the Federation Frigate which has three possible skins) and how each will be labeled in-game. They can choose from any of the NPC contacts or costumes created by the author.
4) The author chooses a faction symbol for it, from any of the pre-existing ones. They can also choose what text will appear if the player hovers their cursor over the symbol (for example, Terran Empire).
5) The author chooses whether the mob will be friendly or hostile to the player, and to the other mobs in the mission.
*Authors can also use pre-existing mobs as a template.
**Including the unusual ones, like the TOS phasers or the Borg Cutting Beam.
And that's pretty much it. What do you guys think?