Hi Sandra!
Stitch is my family's favorite Disney character! We even named our dog after Experiment 626, though thankfully he isn't quite as mischievous as as his namesake.
In typical Stitch fashion, sometimes finding him can be somewhat of a scavenger hunt. He does have a dedicated meet and greet location in
Magic Kingdom Park where the old Stitch's Great Escape attraction used to be in Tomorrowland, however, he was not greeting guests when I was there last month leaving me to believe the location might be open seasonally. I am not able to tell you if it will be open during
Mickey's Not-So-Scary Halloween Party or not since the attractions and offerings for that event have not yet been released.
Another seasonal location for meeting Stitch is at
Disney's Typhoon Lagoon Water Park. Here you can find Lilo as well, but they are only greeting seasonally and usually in the summer months.
If you happen to be at the right place at the right time, you might be able to find Stitch during a spontaneous Character Palooza. I have stumbled across these Character Paloozas twice at
Epcot and twice at
Hollywood Studios. Basically it's a handful of characters, usually rare ones, that come out for pictures and autographs in a random location in a park. I have met Mushu, Bert, Evil Queen, Mulan, King Louie, Max and Stitch to name a few. Since these Character Paloozas aren't scheduled, it's difficult to know in advance if there will be one on the day of your visit and if Stitch will be one of the characters featured, but they are super fun if you ever happen to find one!
The failsafe for meeting Stitch is
Best Friends Breakfast featuring Lilo & Stitch at 'Ohana at Disney's Polynesian Village Resort.
I hope you're able to track down Stitch during your October vacation!
Have a magical day,
Leslie