Fantasy One-Shot

The PCs are are cursed goblinoids who must defend a legendary palace. The mood might be... deadly serious
There is a dangerous group of goblins who hates one of the characters. they are part of same organisation as a character.
The characters start on a sinking vessel. Partway through there is a significant change of weather. If things slow down a ghost gives them aid.
It finishes with a reward of lots of gold. Possible sequel... same villain in a new base

The PCs are all undead who must create a safe place for an elven horse. A character is being hunted by a a vain marshal. It might involve lizardfolk.
There is a repulsive necromancer who wants to do the same thing.
The characters start with an escaped beast. At some point foes try to ambush them. If things are going nowhere there is a explosion.
It finishes with a reward of a magical tower. Possible sequel... a clue from a reward or treasure points to an infamous dungeon...

The PCs are hungry criminals who must explore a warded ruined keep. It might involve bears.
There is a repulsive assassin who works against them.
The characters start running away from something. At some point foes try to ambush them. If things slow down they discover an unexpected place to rest.
At the end there is a reward of a big favor.

The PCs are evil halflings who must escort a wagon through the wilderness. The mood might be... deadly serious
There is a ruthless warlock who has important information for them. they are the cousin of a character.
The characters start with an explosion. Early on they encounter a summoning trap. If things are going nowhere an old friend appears.
At the end there is a wedding. Possible sequel... a character's homeland is under threat

The characters are mercenary guild artisans who must stock a dungeon for a villain. One or more characters has an inquisitive mount.
It is at an ancient castle which is built on the site of an ancient graveyard.
There are criminals partway through a migration. And a cyclops seeks to solve mystery of a missing god.
At some point it starts to snow.
As the adventure progresses a portal slowly starts to open