One Page Lore: Fantasy Folk is a system-neutral deep dive into a number of fantasy species, focusing primarily on physical traits and their direct ramifications rather than assigning anybody a bland monoculture.
Basically, it'll tell you that fungusfolk get drunk really fast and that they only live for about a year, but it won't pidgeonhole them into "these walking boletes all believe you should adopt pigeons" or the like, thereby leaving you a bit more room to figure out where you want them to properly fit in your game world.
The PDF is 50 pages, with solid layout and a nice cover, although there's no internal illustrations. And again, it's system neutral, so you can use it to guide a DnD setting, or a Fate one, or a Ryuutama one, or whatever you've got on tap.
Probably the biggest selling point for this supplement is its creativity. There's a *lot* of cool flourishes and details you can use for RP (or worldbuilding, if you're the GM.) Mushrooms having short lives is one, but there's also stuff like dwarven aging hitting all at once and turning them to stone, and elves being cold-blooded and having mantis shrimp spectra eyes.
Probably my favorite bit is about Halflings, who sleep like cats, taking dozens of naps over the course of a day but never getting anywhere close to a continuous eight hours of unconsciousness.
It's fun and it feels fully fleshed, although it may take your setting further in the direction of weird cosmopolitan fantasy and further away from beards and studded leather armor and quests if you lean all the way in.
Overall, I'd recommend this to anyone who's putting together a fantasy campaign from scratch. Even if you use none of the details from it, it does a good job of getting you to think about the nuances of different species, which also might be useful if you're new to homebrewing races but thinking about giving that a shot.
-Page 6, lifecycle, para 3, "potent for them. come from the" fragment