While Halloween is not generally celebrated in post Horrors America, it is celebrated in the Deep.
It is a festival of make believe, wilderness, monsters.
People are encouraged to create, wear, and trade garish costumes. With costume contests being a thing in some circles. Others use costumes as another form of self expression, a reclamation of fears and freedom.
There's also an abundance of treats curated specifically for the season. Pumpkin stew, turkey roast, spiced cider, baked apples, Despression cakes, ect.
There's also no short of alcoholic beverages. Most of them are also flavored for the holiday. Or dressed up a bit.
Though of course if you're a traditionalist, well there's plenty of plain drinks!
Now more about how the Deep Horrors celebrate
Dr. Smiley loves the costumes. She remembers the time when she was younger and Halloween was all about the dress up.
While she's not into it as much as an adult, she still loves dressing up her dolls. She has an entire bin of costumes that she shuffles through them. She also loves helping people dress up their prosthetics.
The Unsightly Jester is not into the Halloweenness of Halloween. Rather ey are into the tricks aspect. Jester loves setting minor pranks and decorations. One of eir favorite pranks is to joke about being around for the holidays Creation.
Colis hates Halloween. Holidays themselves are a sore subject. But this festival in particular erks him. It's literally admiring demons! He will very vehemently refuse to participate, which is fine by the rest of the Deep. To distract himself, he makes his own spiced cakes to sell.