He can crush and absorb those he sweeps up in his acidic pseudopods. His amorphous body is difficult to damage. Most weapons barely harm him and blunt weapons are just useless, worse though is his powerful acid which tends to consume or ruin anything that touches him. Juiblex can spew forth green slime at foes and summon both oozes and demons to aid him in battle. Usually the oozes or tanar'ri keep his enemies busy and then teleports away to recover.
Of all the demon lords of the Abyss, Juiblex, is perhaps the simplest (and therefore easiest to understand) in his goals. Put simply, Juiblex has no goals other than to simply exist, destroying and killing and corroding anything he can get his tendrils around. he hates everything and revels only in destruction. Juiblex shares the 222nd layer of the Abyss with Zuggtmoy, the Lady of Fungi. The two demons have a long history of conflict and war, with Juiblex's constant attempts to surge upward into Zuggtmoy's holdings a constant source of contention between the two. Other demons despise and loathe Juiblex, yet most see him as a faceless menace that poses a threat only to those foolish enough to stand in front of him, and they wisely choose to leave him alone. There is no organized cult of Juiblex, although a few demented souls do revere the Faceless Lord as a god. It's doubtful that Juiblex knows of these few, and if he does, he certainly doesn't encourage them or reward their loyalty. His primary minions are the countless slimes, oozes, and jellies that shudder in the depths to serve the Faceless Lord willingly- a unique demonic black pudding known as, Darkness Given Hunger. Clerics of Juiblex have access to the domains of Chaos, Corruption, Evil, and Ooze. His symbol is that of a pseudopod dripping slime.