Greeting Gloria, and welcome to planDisney!
As a connoisseur of costuming myself, I'm ever so thrilled to be able to answer questions for folks looking to dress their best over the course of their visits during
the spookiest season at Disneyland Resort. Now when you take a look at the posted
Hours & Events Calendar for a date when the party takes place,
Park Hopper availability prior to closing does seem to make it possible for folks who want to quickly wander their way over after
spending a few frightful hours of the night at Oogie Boogie Bash.
That said, I reached out to a
Disneyland Guest Relations Cast Member who let me know that since we don't quite know what your full costume looks like, it's hard to say whether you'll be permitted entry as it depends on whether it'll be contrary to the official
policy for Theme Park attire as you make your way over to Disneyland Park. They pointed out that the
Disneyland Resort Costume Guidelines apply to guests who are attending Oogie Boogie Bash while they are inside Disney California Adventure Park, and that it'll ultimately be up to your judgment and the discretion of the Cast Members and their leaders at the entrance to Disneyland Park who may ask you to modify parts of your costume before entry - depending on how extensively or intricately you may be dressed.
In my personal experience this month we've definitely witnessed park-goers wearing costumes as they've hopped over from their Oogie Boogie Bash revelry, however these were mostly outfits that were
more inspired by their favorite characters as opposed to complete reproductions that might fool a fellow guest. If you think it's worth the risk with the limited time you'd have spent at the party itself, just be prepared in the event that you're asked to change your look whether in parts or in full! If you ever get the chance I highly recommend heading out to
Tokyo Disney Resort where adults are quite a bit more free to dress in costume during the Halloween season, and live out their cosplay dreams! But no matter what you decide in the end, I wish you all the best in your quest to be well-dressed at the Happiest Place on Earth.
Happy Haunting!
Prince