Assuming you have a room and know how to create models you can now get them to do your every bidding through aiscripted sequences. First of all, consult this list for all the models and animations you can use in a single player map:
http://www.planethalflife.com/workshop/models/ssec_docs.htm
You get them to do these animated actions through the
aiscripted_sequence entity- the model will perform the action at the exact location of this entity. Always remember to keep the model about a unit above the floor:
Give your target monster that you want to perform the action a
name, e.g.
bob. Now give the aiscripted_sequence a
name of
a1, and in the
target monster box type
bob. Now the
move to position field is quite obvious, so select how you want your monster to move to this spot before they carry out their sequence. Then you may pick an action animation for this model noted in the site above and put it in the
action animation field.
Finally, you need to trigger your aiscripted_sequence entity, which you might want to do with
trigger_once entities so the action is only performed once!