D&D One Shot

The PCs are shapechanging bards who must survive a slaad apocalypse. Two of the characters have fallen in love. It might involve a cult.
There is a drunk orc warchief who works against them.
The characters start at a party that is disturbed. Early on they encounter a natural barrier blocking their path. If things are going nowhere a chase starts.
Afterwards there is a reward of membership of an elite group. Possible sequel... an NPC from the adventure hires the characters for something totally different

The characters are shapechanging folk heroes who must escape from a legendary underwater city. Two of the characters have fallen in love.
It is at a haunted crypt which is protected by a poltergeist.
There are halflings burying something. And a mine seeks to subdue a spectral sorcerer.
At some point someone has/remembers a dream.
As the adventure progresses people start to gather for a wedding

The PCs are egotistical warlocks who must survive a tavern crawl. A character is possessed by a ghost. It might involve undead.
There is a loud dragonborn witch who comes with them. they are part of same faction as a character.
The characters start with the loan or gift of a powerful magic item. At some point they meet a friend of a character. If things get stuck a friendly animal leads them in the right direction.
Afterwards there is a newborn or child on the way. Possible sequel... one or more characters start having dreams related to a monster from the adventure

The PCs are fiendish halflings who must survive a magical plague. It might involve dark elves.
There is a hedonistic priest who hates one of the characters.
The characters start with an attempted theft. At some point they encounter a summoning trap. If things slow down a character learns something useful with a Nature check.
Afterwards there is a funeral. Possible sequel... a clue from a reward or treasure points to an infamous dungeon...

The PCs are working for a powerful faction who must put on a fashion show. A character is possessed by a ghost. The mood might be... tense
There is a brash healer who works against them. they are part of same religion as a character.
The characters start during a heist. At some point there is a romantic complication. If things get stuck a character learns something with a successful skill check.
Afterwards there is one of the characters dead or unconscious. Possible sequel... a clue from a reward or treasure points to an infamous dungeon...