The Hat Man's Hat

The signature tall, buckled hat of the The Penway Hat Man, claimed by Thalia after she killed him in Session 43. It is a fey-flavoured magic item holding a pocket-void — a weightless, spiralling pink-black-and-purple abyss with a single head-sized opening. Anyone who fails a save against the thrown or worn hat is sucked inside, where there is no leverage to move (you spin and drift, going nowhere without something to anchor to) and a victim is lost forever after ~10 minutes. Its wearer can fold themselves into it, throw it, and reappear where it lands. It is sturdier than ordinary gear (resistant to fire and damage, not destroyed by a torch). The void is littered with the half-decayed corpses of past victims; turning the hat inside out (like a bag of holding) dumps them — and anyone inside — back out.

(Used against the party all of Session 43 — it trapped Jex, Salamandine, and Thalia in turn before Thalia took it as loot.)

Session 43 (acquired)

• Won by Thalia from the slain Hat Man, who'd repeatedly used it to hat-nap her allies into the void.
• Attunement: the GM rules that after a rest Thalia (a fey) can enter and leave it at will rather than being helplessly sucked in — though staying inside too long still means ceasing to exist.

Session 44 (attuned & enchanted)

• Attuned. Thalia attunes the hat over a short rest, getting to choose its size, shape, design and colour (so long as it stays a "big hat") — and can now enter, exit and travel via it at will.
• The no-vanish net. During the downtime she pays Renforth ~300–500 gold to enchant it with a thorned net so anything (or anyone) caught inside no longer disappears forever — turning it into a usable storage container that holds objects up to roughly a 10-ft ladder in size (but not a whole person, and not a piano), with "a little bit of cartoon physics."

Session 54 (used as transport, and as a plan)

• A way past a flooded crawl. Rather than stomach-crawl a submerged 20-ft tunnel into the bone dragon's lair — cave-ins and drowning at once, her two worst fears — Thalia folds herself into the hat, has it thrown to the far side, and climbs out there, keeping the whole crawl inside her 30-ft Pass Without Trace.
• A cunning action. Mid-fight she rolls into the hat on her turn, then leaves it 5 feet away as a bonus action — the GM: "it's like a really hard-work rogue cunning action to disengage."
• The combo the GM wants to see. Paired with Lash's new Gravity Gauntlets: Thalia opens the hat, Lash aims the 20-ft pull at the inside of it, and everything within 20 feet is vacuumed into the void with no saving throw. "Yeah, do you think it fits? That's pretty sick, I think." Untested.
• Also floated and dismissed: whether the bone dragon itself would fit. It would not — the hat's net tops out well short of a boss-sized wyrm, though putting only its tail in was considered a legitimate way to pin it.

Session 55 (the rules for posting a person)

• Used to save a bystander. With the level-2 scientist Polos prone and about to be eaten by the Morkid, Thalia skipped the explanation — "hold on to the brambles!" — and simply put him in. He came out afterwards with a complaint ("there's no air in there") and an admission that he had been screaming the whole way in.
• The mechanics, settled at the table. Medium or smaller creatures only; larger ones cannot be put in at all. A willing creature costs one of her two attacks, the same as a shove. An unwilling one is a contested check (a grapple-style contest from within 5 feet) and probably her whole action. The party's own read on the air supply, by analogy with a bag of holding: about 10 minutes, divided by the number of creatures inside.
• Its declared, legal contents. Asked why she owns a hat people can go in, Thalia's answer is a storage inventory: her tea set, and "the undelivered mail. Not that I deliver mail, because that would be illegal. That's why it's undelivered."