By Nick Olivo
There are certain monsters that have become iconic bosses throughout fantasy RPGs. Crazed human necromancers, cunning mind flayers, crime lord beholders, and of course, dragons. While these are fun and exciting creatures to pit your players against, sometimes it’s fun to throw them a curveball, and set them up against a monster that no one would suspect capable of pulling the strings. And today I’m talking about an ooze.
Just about every campaign comes across an ooze at least once. Take the gelatinous cube, so famous it made a cameo appearance in the movie Onward, or the dreaded black puddings that corrode the PCs’ weapons when they attack it. When I guest DM’d for Authors and Dragons, I hid oozes in fonts of water outside of a temple. When Silas Kane, the party’s paladin, got close enough, the ooze leapt from the water and engulfed his head. He spent the next few rounds bashing his own face against the font to try and get the ooze off. Good times.
So your players likely have familiarity with oozes and they know what to expect. Oozes are mindless slimes that it’s best to attack from a distance and that’s about it. The party would never suspect an ooze of being capable of thinking in sentence fragments, let alone scheming any kind of plot.
Until they meet an oblex, that is.
Oblexes were introduced in Mordenkainen’s Tome of Foes and are oozes that were likely created by mind flayers, though Mordenkainen himself suspects that the ooze lord Jubilex had something to do with it. Oblex feed on the memories of their victims, absorbing their skill proficiencies and knowledge. They also have the ability to create ooze-based copies of their victims, which helps them attract and hunt additional victims more effectively. The more memories an oblex consumes, the larger it gets, and eventually, it spawns a new oblex.
But here’s why I say that they make great unexpected bosses. Even a newly spawned oblex, which is a CR ¼, has an INT score of 14. While that’s not genius level, it’s smarter than many other monsters (and a lot of PCs) at that level. By the time the oblex reaches adulthood, its INT score is a 19, which is the same as a mind flayer. An elder oblex has an INT score of 22, which is beyond the level of intelligence any PC can achieve without magical items. So this is friggin’ smart ooze. And more than competent enough to craft schemes that harry the party. They’re also the only ooze I’ve come across that has an alignment (lawful evil), so this is a creature that knows right from wrong, and it chooses wrong.
In combat, an oblex is no slouch either. Adult and elder oblexes have innate spellcasting abilities, your basic pseudopod attacks, and the ability to drain the memories of a creature that’s within 5 ft of it. This deals psychic damage and the PC must roll a die and subtract the result from any ability check or attack roll they make. Each time the PC gets drained, the size of the die increases, starting at a d4, going to a d6, and so on, until you get to a d20. That’s a terribly debilitating situation to be in, and because the oblex has access to spells that mentally dominate, confuse, or paralyze the party members, there’s a good chance at least one PC is going to get hit pretty hard by this.
So imagine a town where people have trouble remembering things. The PCs investigate, and they find that something’s been tampering with peoples’ minds. Maybe some of the people have recurring nightmares about a squid-headed humanoid. The PCs will suspect a mind flayer, and you can even have a mind flayer working for the oblex. But then, when the PCs find and defeat that mind flayer, things don’t change in the town. And that’s when they get the reveal that the mind flayer was working for something else, and now the party has to figure who that is. And when they realize it’s an ooze, their minds will be blown.
Moments like this can be very exciting for the party and you as the DM. Planting red herrings and watching the party come across them, discover the truth, and then have the “Oh, crap,” moment as they realize the villain isn’t who they thought it was, is tons of fun. When a movie has a surprise villain, like The Usual Suspects or Unbreakable, the audience gasps and then spends hours afterwards reexamining everything they thought they knew, and then they realize that the answers and clues pointing to the real villain were right in front of them all along. Your players will do the same thing.
So sure, have the PCs test their wits and strength against beholders and dragons and necromancers. But throw in an oblex to keep your party guessing, because really, who’d suspect an ooze?
