D&D One Shot

The PCs are evil spellcasters who must survive a long coach chase. A character is being hunted by a monster. The mood might be... relaxed
There is a desperate apprentice who turns out to be the villain.
The characters start in a tense stand-off. At some point they encounter a riddle. If things get stuck they discover a magic item.
It finishes with the characters starting a journey.

The PCs are mutant lizardfolk who must rescue their mentors. It might involve zombies.
There is a charismatic paladin who comes with them. they grew up with a character.
The characters start during an attempted escape. At some point foes try to ambush them. If things are going nowhere someone has/remembers a dream.
Afterwards there is someone imprisoned.

The characters are secretive barbarians who must protect an overgrown volcano.
It is at a sacred island which is protected by an awakened shrub.
There are a pack of unfriendly spies starting a journey. And a lizardfolk shaman seeks to destroy a cursed collection of trophies.
At some point someone discovers something unexpected in their pocket.
As the adventure progresses a portal slowly starts to open

The characters are hungry ogres who must break a curse at an enchanted castle.
It is at a part-buried hill which is in an area affected by a mirage arcana.
There are a group of unfriendly bandits looking for buried treasure. And a demon wants to secure a dwarven pet.
At some point there is a strong wind.
As the adventure progresses people fall ill

The PCs are good orcs who must create a safe place for a legendary cat. It might involve water.
There is a ruthless barbarian who wants to do the same thing.
The characters start running away from something. Partway through they encounter a symbol spell. If things are going nowhere an ally turns up with useful information.
It finishes with a newborn or child on the way.