Yeah, that's in the archive too, I think. Gender-swapping abilities. And when it engulfs you, it makes you orgasm..yadda yadda yaddd. Now, look at this instead:
Juiblex has many slime, pudding, ooze, and jelly "servants," although none are intelligent enough to serve the demon lord willingly -- except for one.
Darkness Given Hunger is the largest black pudding known. It was possessed by a demon at Juiblex's command, and then an imprison possessor spell was cast upon the fusion, making it permanent. For centuries, the demon has dwelled within the pudding, and the two have truly become one in the foul depths of the Abyss. Now, Darkness Given Hunger is Juiblex's main servant, helping patrol the Abyssal layer upon which they both dwell, looking for food.
Darkness Given Hunger: Unique advanced black pudding/demon fusion; CR 12; Gargantuan aberration; HD 30d10+240; hp 540; Init -3; Spd 20 ft., climb 20 ft.; AC 7, touch 3, flat-footed 7; Atk: +25 melee (2d8+10 plus 2d6 acid, slam); Face/Reach 20 ft. by 20 ft./15 ft.; SA acid, constrict 2d8+10 plus 2d6 acid, improved grab; SQ blindsight 60 ft., immunities, split; AL CE; SV Fort +16, Ref +8, Will +13; Str 25, Dex 4, Con 24, Int 12, Wis 14, Cha 11.
Skills and Feats*: Hide +11, Move Silently +27; Cleave, Improved Bull Rush, Improved Critical (slam), Iron Will, Lightning Reflexes, Power Attack, Thrall to Demon.