itch.io

It looks like it's a module for possible monsters to add to sessions. I'm not too familiar with other ttrpgs but they're pretty common for Mothership.  Their core set has a monster compendium called Unconfirmed Contact Reports that has a similar setup of description and stats.

Thank you for taking a look! This is not a stand alone adventure. It's more like a "bestiary" of potential monsters that you could use in your game.  It's designed with sci fi horror rpgs like Mothership in mind.

In concept it's similar to stuff like this https://www.tuesdayknightgames.com/products/mothership-unconfirmed-contact-repor... but more garbage ;)