Hi there Bianca,
Welcome to planDisney and thanks so much for your question! I'm a huge fan of
Oogie Boogie Bash - A Disney Halloween Party, so I'm excited to hear you're planning on going during its opening week!
I'm also happy to share that, although the
Halloween season doesn't officially kick off at the Happiest Place on Earth until Friday, August 21,
Guardians of the Galaxy - Monsters After Dark will be running during the Oogie Boogie Bash events on August 18 and August 20. You can see this as well on the attraction page that I linked above if you select August 20 in the date selector near the right side of the page.
There are a lot of other really fun aspects to Oogie Boogie Bash like the various treat trails, fun and unique character appearances, and Villains Grove! Also don't forget that your event ticket also grants you access to California Adventure Park starting at 3:00 PM if you want to get there early to experience the park.
When I last went to this event with my son, we tried a strategy where we started in the back of the park (in Pixar Pier) and worked our way to the main entrance by the end of the night. Our thought was that most of the crowds would likely start at the front and work their way to the back of the park. It was still a busy night, but the strategy seemed to work well for us!
Make sure to keep an eye on the
Disney Parks Blog for more information about this fun special event as it gets a bit closer - I'm specifically looking forward to the Disney Eats Foodie Guide that will cover all the themed food and beverages.
Thanks again for your question, Bianca! I hope you have a wonderful time on your upcoming visit.
Have a Magical Day,
Greg