Hey, I am actually not sure why he's not there yet. He will show up soon in the Commons, because I didn't see him either. Wait a couple of days, like maybe 3 days, he'll pop up. In the meanwhile, have fun.
The Halloween events don't usually get started until after the first Monday of October. Last year, that was the 3rd. This year, it might happen as early as tomorrow, or maybe as late as next week (the 9th).
Alia Misthaven