The creep itself must be owned by one of the neutral players (black), who are also hostile against you. However, I strongly recommend you to trigger up the bounty system.
To make them drop items upon death, simply see the item itself and check the "Dropped When Carrier Dies". Then simply see the properties for the creep and add the item to the list. If you spawn the creep through triggers, just make another trigger which creates a new item and gives it to the target.
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.
I'm on a page about incorrect corrections, and spent the better part of like two hours trying to get someone to understand that -5^2 = -25, not 25, and then that post had comments get reposted because that group is self sustaining, and that person was in turn trying to explain what I just explained to them. And I'm taking that as a victory