Ynas Midgard got me thinking about monster design, by asking how to integrate monster PCs with the class construction table. Monsters which are, basically, fighters progress as fighters, when used as PCs, and those that are basically magic-users progress as magic-users. By extension, monsters that have thiefly powers should progress as thieves, but there are very few of these; perhaps there should be more, as well as thief variant monsters. And monsters that mix classes could progress as a hybrid, as defined by the class construction table.
But there aren't any clerical monsters. There are some which use cleric spells, but I can't think of any monster that turns undead. Possibly because the overwhelming majority of monsters are intended as enemies of good. But if you start thinking in terms of clerics without spells and re-using the turn undead mechanic to implement other abilities, it seems like there's a huge opportunity to simplify some monster abilities and create entirely new monsters using that approach.
Take for example creating and controlling undead, instead of turning undead. I whipped up a necromancer class based on the turn undead mechanic, but necromantic monsters are also a possibility; I didn't officially stat up necromatoads/necrotoads, but the basic idea was to let toad necromancers use the turn undead mechanic to create or command undead, creating trouble for PCs. Dryads could be rewritten to use turn undead as their charm mechanic. The storm fiend write-up has the weather shifts as automatic, but if a player were playing a lesser storm fiend as a PC, the weather-worker class would be a good option.
This has given me some ideas to create several new monsters, exploiting the turn mechanic for other purposes. Expect to see some in the next several days.