Base on the information available on their forums, (Yes, you read that right, CABAL Forums is now accessible) here are the list of items that you can obtain:
I immediately logged-in my character in search for the pumpkins. Well, you can say that the Jack-O’Laterns are easier to find than the previous Crag King Turtle (Well, the Turtle is a boss monster). These pumpkins are not that strong but has a high defense, my damage is only 1 (I don’t know about the others). If ever after defeating Jack and drops an item called “Halloween Trick Ticket”, don’t bother getting it since it’s not that important and it won’t give anything. Why? Because it is written in its description that the item is called “Better Luck Next Time! So, yeah, don’t grab that one.
This information will provide a simple demonstration on how to claim rewards from “Event Girl Yul”, First talk to her and click the Level Rewards, next click the [Check Goal/Participate] and you will see the list of levels where you can obtain rewards starting from level 31 up to 190 which is also shown below:
If you still don’t know, CABAL Online will be available on Steam soon. They just got greenlit last October 2nd on Steam Greenlight.