I recently ran a one-shot of Tiny Cthulhu, the Tiny D6 Mythos horror RPG from Gallant Knight Games.
It’s a super-light system, quite good for one-shots.
I ran the published adventure Sister of Yhanith’lei. It’s about a expedition to a supposed shipwreck off the coast of Arkham. It’s a short scenario, easily run in a few hours. It’s a bit on the railroady side, but still quite fun. I’d recommend it.
There are 4 pregenerated characters provided with the adventure. I’ve copied the character stats onto my custom Tiny Cthulhu character sheets, along with a custom character of my own design.
I’ve uploaded individual sheets for each character that are still fillable, and modifiable. You could also import a character image into the upper right corner. I’ve also combined them all into one non-fillable PDF.