Intelligent ooze or cube from old 3.5 campaign

Question

Many, many moons ago I was DMing a long term party through a D&D 3.5 campaign.

I used a number of modules - Sunless Citadel, Forge of Fury, etc - as the general setting and backdrop.

I remember at one point dropping my party into a cave/old temple infested with oozes and gelatinous cubes. One of - I think the cubes - had oddly high intelligence so I ended up role playing them into a fun character that joined the party for a while.

I'm now writing a one-shot where I would like to use him again and wanted to look up the original setting and flavour text. Does such an NPC ring any bells for anyone?
I haven't found him yet flicking through some of my old modules.

Answer 1

I realize that we already have an accepted answer, and the actual answer wasn’t from 3.5e to begin with, but for the sake of completeness, we also have a list of intelligent oozes from D&D 3.5e:

Intelligent oozes, including gelatinous cubes—not officially playable

One of the hard, practical stops on playing any monster is Intelligence—even if you ignore the rules saying you’re not allowed to play one, you can’t really turn a mindless creature into a player character. Most oozes—including the gelatinous cube—are mindless, but D&D 3.5e does provide ways around that.

For example, there’s the awaken ooze spell (Dragon vol. 304), or the sentry ooze template (Dungeonscape), though the latter only provides “animal-like” Int 2. There are other templates that are not specific to oozes, but still legally applied to one, that provide more Intelligence. Ultimately, however, none of these rules officially make the cube playable.

Wizards used those same ideas in its own “Elite Opponents” article that includes a gelatinous cube monk, but it’s not playable either—monsters could take class levels in this edition. It gets around the gelatinous cube’s lack of Intelligence by using the fiendish creature template. They did similar things with other oozes in another “Elite Opponents” article.

There are also various oozes that are intelligent by default, mostly in Monster Manual II and III. These aren’t playable either.

^{(My answer to “Have oozes ever been a playable race?”)}

So far as I can tell, those Elite Opponents articles are the only times Wizards of the Coast wrote up an intelligent ooze NPC for 3.5e.

Answer 2

I had misremembered the edition where they encountered the cube in question.

It was actually the named NPC "Glabbagool" from the Out of the Abyss adventure. He was a gelatinous cube that had gained sentience due to the return of - I think the demon - Jubilix to the Underdark.

Very fun character.