In vanilla Morrowind, creatures do not have Disposition, Factions, nor the ability to use dialogue other than what has been assigned to their ID. This potential workaround does the following:
- Spawns in an invisible NPC of custom race each time the creature is activated.
- Gets a saved dispostion value from a creature variable, then greets the player.
- Updates the creature's disposition variable before deleting itself.
Since the NPC is doing the talking, they can use general dialogue, have a faction, disposition, and can have race-specific dialogue assigned to their race. By placing and removing the NPC each time, this allows for moving the creature around from cell to cell. The NPC can also tell the creature if it has been successfully taunted to initiate combat before self-deletion. I have included a very short quest to showcase this functionality.