While I don’t recommend the following, it has been known to be very effective. Make a plan. As example, first, offer the bad guy a “peace offering” consisting of brownies, made by “yer mom” but which contain a large volume of some chocolate flavored laxative. Perhaps you could say something like, “sorry dude, we got off on a bad start. Here’s a peace offering. Enjoy!” Don’t give him too much as you want no evidence left over, or even worse, you don’t want “Derrick” to give anyone some of the brownies.
Then, consider talking with your manager. Think about if you want the job enough to do this: If you talk with the manger, tell the manager of the repeated bullying, harassment and assaults, the laziness of the guy, and relay to the manager that if the guy isn’t stopped that you’ll get your family’s attorney to talk with the manager. Also read the estimated time to effect on the box the laxative came in. If you time it right, the manager will be talking with “Derrick” about the time the laxative hits.
I also agree with the others that the job isn’t worth this effort. Note that if you do give him tanted brownies, you are effectively poisoning the guy. There are severe risks associated with doing this, if you are caught
You are obviously motivated, and will have little or no problem finding another job. Another significant point in all of this is that if you have the talk with your manager, it is possible that the conversation will be noted somewhere, and if you refer back to this place for a reference, that could come up.