Today's
Monster Monday is the hellmouth, a tremendous beast whose very mouth is a gateway to Hell (as you may have guessed from the name). Hellmouths were a motif in medieval art that tended to result in some pretty metal images, as in this detail from an icon showing a black hellmouth swallowing a bunch of damned souls, who are also simultaneously being roasted in flame, tortured by devils, and/or attacked by snakes:
As it is statted up below, the hellmouth is not a monster the GM should use lightly. It is always important, when designing encounters, to take into account what might happen if one or more of the characters succumbs to the monster's powerful abilities. You don't want to throw a medusa at your players if you aren't prepared to spend some time with one or more of them petrified. Just so, you don't want to throw a hellmouth at your players if you aren't prepared to spend the rest of the session with half the part stuck in Hell. The hellmouth is best used when necessary as part of the story, rather than as a random encounter. That said, suddenly having to improvise a rescue mission to get your bard out of Hell sounds like a pretty fun session.
The hellmouth does not have to be a potential campaign derailer. If you aren't ready to randomly throw some of the PC into a screaming torture-dimension, the hellmouth can suppress its throat-gate, allowing it to simply swallow folks into its flaming stomach. It is also designed to act as a living infernal siege engine, launching flaming boulders at distant targets and calling in reinforcements from Hell.
By the way, I've decided to start giving some adventure hooks below each monster, so even if you don't feel like reading a stat block, scroll down for dem sweet hooks.
The following text in
gold is available as Open Game Content under the
OGL. Open Game Content is ©2017 Jonah Bomgaars.