From TDN

There are the following default "Actor" types in the Torque AI Pack v1.0

Citizen

This is a default "villager" type. Uses the "Citizen.fsm" script and basically acts like a villager in that it shops (if any shops are nearby DefiningAIInterestObjects) it also will stand and converse with other citizens close by if it feels like chatting. Finally, it will become freightened if it is hurt by anything and will try and run away from any attacking creature until it feels it is safe again, other than that it is pretty dumb and will sometimes just decide to stand and think (unfortunately usually to no avail).

MeleeMonster

This is a default monster which attacks when anything it classifies as an enemy comes within activation range of it. It also has a "rage meter" which builds up as something attacks it, but then recedes when it isnt directly under attack, so slowly it is appeased and goes back to its usual routine, which typically involves sitting down and sleeping.

RangedMonster

This is the same as a melee monster, apart from is uses ranged attacks and generally tries to keep itself at range from its attacker.

Guard

Very similar to a melee monster, however it has a specific point that is likes to guard. It also will aggro anything that comes within range and attacks anything else. So its generally not a good idea to be battling in front of this thing.