D&D 5E Little-Known Monster Facts

[CM]

What are some minor ways in which you've tweaked a monster to give it a whole different feel?

Not looking for major mechanical overhauls or complex stat blocks, but just simple things like a modified ecology, an added power, or similar such things that leave the monster largely the same but give it an interesting twist?

My example is with the bulette. I'm running a campaign set in FR's Neverwinter during the 4e era (though using 5e rules). Part of the city still lies in ruins, and a gaping chasm in one ruined city district allows all sorts of Underdark creatures to occasionally come to the surface. The party was pursuing a group of arsonists from the local thieves' guild into the (walled-off) district and came across their (rather messy) remains being picked over by a pack of rust monsters, with signs that a a huge burrowing creature of some kind had killed them.

The rust monsters were fairly easily dispatched with only minor equipment damage (the dwarf paladin kept sanctuary up the entire fight), but the combat awoke the huge, spellplagued bulette that was nearby, sleeping after its big meal. It chased them almost all the way back to the "safe" district of the city, but luckily for them they ran into a pack of ghouls on the way, which distracted the bulette enough that it ended its pursuit.

The ecology change I made is that bulettes and rust monsters live in a (mostly) symbiotic relationship. Bulettes will allow rust monsters to crawl over them, removing arrowheads and broken blades from their hides, and metal armor fragments from their teeth, while (usually) not eating them. The rust monsters can smell bulettes from up to a mile away and will be naturally drawn to one, following it around at a safe distance and waiting for an opportunity to scavenge a meal.​

So what other little-known monster facts are out there?

 

[FormerlyHemlock]

Stirges are the larval (pre-wyrmling) stage of dragons.

I've stolen a bunch of stuff from HackSlashMaster: http://hackslashmaster.blogspot.com/2013/11/on-ecology-of-troll.html, http://hackslashmaster.blogspot.com/2013/12/on-ecology-of-vampire.html, http://hackslashmaster.blogspot.com/2013/10/on-ecology-of-stirge.html. For example, in some of my campaigns, trolls and vampires are related. I haven't used this one yet but I'd like to: "When reflected in a mirror, a troll is a startlingly beautiful humanoid. If pulled through the looking glass, they will trade places with the ugly one. In every other way, they are identical, including outlook, alignment, and disposition."

Also, my demons are not actually immortals, reborn back in the Abyss when slain. They are just born from the fires of chaos believing themselves to have lived before. It makes them reckless, destructive, and fearless.

 

[Redthistle]

Back in the 80s, I had played the solo adventure, Maze of the Riddling Minotaurs.

When I adapted it to run it as an adventure for my group, I needed to add some additional riddles, a form of humor that's never been my long suit.

One of the riddles had something to do with blood, and the players jumped all over it as being culture/setting-anachronistic. One even asked, "So, minotaurs in your world are all hematologists?"

They nailed me good on that one.

Ever since then, however, I've had an occasional minotaur show up in a medieval version of a white lab coat.

 

[Redthistle]

In 4e, there was an assassin build for the rogue class. One of the Paragon Paths included a type of assassin that could capture the soul of a creature it killed.

I used that idea of capturing a soul as a prerequisite for the creation of any warforged PC/NPC. It could only be done using ritual magic, so that type of assassin would work in collusion with a cleric of suitably nasty alignment.

The soul would be infused into a ghulra, allowing the "living" part of a living construct to become awakened.

In my game world, it was duergar who introduced warforged to the world. They were getting tired of the expenses involved in gaining and maintaining slaves, and came up with the idea of sacrificing and transforming fully living thralls, when they reached the end of their physiological usefulness, into more durable and less fractious slaves. For the duergars, it was a cost/benefit win-win solution.

 

[pukunui]

[MENTION=6778305]Redthistle[/MENTION]: Reminds me of how golems were created in Dragon Age. I've been using that as a way to explain how warforged were created for some time now myself.

 

[CM]

The above reminds me: in the same campaign as in my OP, the players were indirectly responsible for the warforged appearing as a race.

They were exploring Neverwinter's ruined temple of Gond, where they found a small clockwork humanoid stashed away in a locked drawer. Along with it was a detailed journal by its creator, a priest named Alcaeus, documenting its construction and its initial activation. The inventor kept it hidden while teaching it how to speak and behave. Apparently it didn't go well, and the construct had to be deactivated. Modifications were made, and Alcaeus was about ready to try again after erasing its memory, but then the volcano north of Neverwinter erupted, destroying most of the city and killing him in the process.

After determining that it could be powered up by placing residuum crystals in a receptacle, they activated it. This time it was able to socialize properly, and after clearing the temple ruins, priests of Gond arrived to rebuild the temple and the party gave custody of the being to them. The church called a conclave to determine the fate of the being, as some saw it as a valuable tool while others argued that it should be recognized as an independent life. The party ultimately persuaded the Grand Artificer to declare it a free and independent being, and "he" immediately named himself Alcaeus (after his "father") and set about constructing a new, adult-sized body to assume. Any warforged in that campaign will be known as Alcaeans and will have been created by him.

 

[Plaguescarred]

Zombies, ghouls or other undead type infested with patch of mold, pudding slime or other parasit can pose an additional threat

 

[Edwin Suijkerbuijk]

One idea I had was to change the ecolegy of the mind flayer.

Tadpoles would chage into intellect devourers, then go out to find humaoind hosts.
After having posessed a host for 6 months they feal the time is right to return to the underdark, the tentacles and full change to mind flayer would happen in the next few days.

 

[Mouseferatu]

Derro aren't corrupted fey or anything so mundane. They're the creations of something from the Far Realm (or distant space, wherever Lovecraftian "old gods" come from in a given campaign). The intent was to create humanoids that could infiltrate existing human/humanoid communities, but the alien nature of their creators, and their lack of proper understanding of humans, resulted in these obviously abnormal, mad psionic entities instead. To this day, though, the derro and their creators don't really understand why they can't pass as normal humans/dwarves/whatever, and their quest to understand that is part of why they kidnap and experiment on people.

 

[Sammael]

Trolls in my games reproduce asexually, through budding. Due to their high mutation rate (which explains the huge number of different troll species), each troll is a different individual, not genetically identical.

Trolls are one of the races created by the Batrachi progenitor race in an attempt to create perfect soldiers. However, when the majority of Batrachi left Faerûn for other planes or the far future, trolls were left behind and eventually bonded with giants (whom they were created to fight). For this reason, many people mistake trolls for a type of giant.

Batrachi themselves split into several branches, broadly defined by the type of experimentation they mastered. One branch, which specialized in trans-dimensional magic, evolved into ethergaunts and spellweavers; another, which favored transmutation, migrated to Limbo where they modified the slaad Spawning Stone and reshaped the slaad races in their image; and yet another mastered psionic abilities and time travel and eventually evolved into mind flayers (doppelgangers, who were also created by the Batrachi, often follow mind flayers for this reason).