D&D 5E Mastermind monsters

[Mouseferatu]

So, D&D's always had a select group of monsters that make fairly good Big Bad Evil Guys--the masterminds behind long-running plots. (For purposes of this discussion, I'm talking monsters only; not humanoids with class levels.)

I'm looking to expand that list for my own campaigns. So, what monsters have you used as masterminds other than those listed here? (Any edition is fine.) How'd it play out?

The Obvious List:
Mind flayers (and related)
Beholders (and related)
Aboleths
Vampires
Liches
Dragons
Devils
Daemons/yugoloths
Krakens
Rakshasas
Genies
Death knights
Doppelgangers

 

[Ricochet]

A Titan who was a good titan but had been corrupted by an evil spellcaster.
A Will o' Wisp who was opening portals and experimenting with creating aberrations as a means to gain godly powers from its new "followers".

 

[Sadras]

So, what monsters have you used as masterminds other than those listed here? (Any edition is fine.) How'd it play out?

Lycanthrope (Werewolf).

The players did not see it coming, I intertwined this with a backstory of a PC (a sword-mage) whose mentor, a dabbler in magic and alchemy, was on the run from crimes in another nation* he supposedly never committed (he did). His student (PC) helped him a handful of times escape from the authorities or provide him with monies. Meanwhile in the campaign they had an ongoing saga to catch a werewolf known as The Hound who was supposedly the mastermind of the lycanthropes in their duchy. Many stories and myths about The Hound were spun. A legendary figure who evaded authorities for well over a decade.

He dabbled in potion-making as he had found an alchemical mixture which could mask the scent of lycanthropes from animals (cats, dog and horses) which was particularly useful. The PC believed he was more of a Don Juan providing potions of "love" and special fragrances to noblewomen and wealthy ladies given what he had seen as his apprentice during 1-2 early sessions. Little did he know he was actually providing masking potions to his were-foxes who were then distributing his wares to the greater lycanthrope network. It was all an elaborate cover.

Years later when the Hound had gone into hiding*, things turned ugly when the PCs managed to track down one of these werefoxes known as the Mistress (who happened to be The Hound's actual lover) and one of the PCs decided to execute her while the others were distracted (This was not planned). In any event The Hound came out of hiding and started assassinating all those that led to the death of his lover one by one - starting off with allied NPCs, retired PCs and eventually he attacked the PCs and his student...twice he tried and twice he was thwarted by some clever role-play, however The Hound was never captured, but alas now his actual identity has been revealed.

* There was a Black Seal Warrant against him (for those who know the Minrothad Guilds)

 

[SirAntoine]

The list is quite inclusive. Demons and yuan ti are other big names. Titans and immortals are other big ones.

 

[PnPgamer]

Slaads?

 

[Hand of Evil]

Rat-folk (skaven) are always out to undermine with their plots and plans. It is not that they want to get rid of the humanoids races, they don't, they want to bring about chaos and ruin.

 

[Schmoe]

Berbalang (see 1e Fiend Folio) - A creature that spends most of its time roaming the Astral Plane via astral projection, and awakes monthly to send forth a physical projection on the Prime for its own secretive purposes. It was practically designed to create plot possibilities.

Barghest - Works great as a leader of a cult whose inner circle get to "transcend" by becoming the creature's next feast.

Githyanki - I've not used them myself, but they seem obvious.

 

[PnPgamer]

More intelligent giants? Such as cloud or storm.

 

[Will Doyle]

Hags make good masterminds. I've not run a campaign with a hag as the *main* mastermind, but I've run plenty of fun adventures with hags as the main villains. A covey of hags could be the mastermind for all sorts of plots.

 

[Will Doyle]

Most of my masterminds end up as humans or elves though