Chimera Spawn of Juiblex
Okay, a much more appropriate version of a creature created by Dog Moon.

I think Kafkonia inspired me a little bit, which is why I like comments [and criticism if constructive]. So I will take a moment to say the following: Thanks for everyone who has commented on this thread and those for those will will continue to comment or who will comment but have yet to do so. [Hrm Jelly Spawn, maybe I should make that into a template, though I could just assume that the Fiendish/Gelatinous combo fits well enough].
And now, the Chimeric Spawn of Juiblex, the Demon Lord of jelly and jelly-like objects, such as this one:
Gelatinous Multiheaded Chimera
Large Aberration
Hit Dice: 15d10 + 90 (250 hp)
Initiative: +3
Speed: 20 ft
Armor Class: 18 (-1 size, -1 Dex, +10 natural), touch 8, flat-footed 18
Base Attack/Grapple: +15/+24
Attack: Bite +19 melee (2d6+5/19-20 +1d6 acid)
Full Attack: 2 Bites +19 melee (2d6+5/19-20 +1d6 acid), 2 Bites +19 melee (1d8+5/19-20 +1d6 acid), 2 Gores +19 melee (1d8+5 +1d6 acid), 2 Claws +17 melee (1d6+2 +1d6 acid)
Space/Reach: 10 ft. / 5 ft.
Special Attacks: Breath Weapon, Smite Good 1/day [+0/+15]
Special Qualities: Blindsight 60 ft, Darkvision 90ft, DR 10/magic, Immune to polymorphing and stunning, Low-light vision, Resistance to Cold/Fire 10, Scent, SR 20
Alignment: Usually chaotic evil
Saves: Fort +14, Ref +4, Will +4
Abilities: Str 20, Dex 9, Con 29, Int 3, Wis 9, Cha 6
Skills: Hide +3, Listen +19, Spot +16
Feats: Ability Focus (Breath Weapon), Alertness, Combat Reflexes (Bonus), Improved Critical (Bite), Improved Initiative (Bonus), Power Attack, Skill Focus (Listen)
Environment: Temperate Hills
Organization: Solitary
Challenge Rating: 13
Treasure: Standard
Advancement: 16-27 HD (Huge)
COMBAT
Heads are Black: 1/1d4 rounds: 3d8 from each of the two heads. Reflex DC 28 for half.
Skills: Chimera gets +2 racial bonus on Spot and Listen. Multiheaded gives it an additional +6 on Spot and Listen checks. Gelatinous gives +4 on Hide checks due to its translucentness.
Resilient(Ex): Gelatinous creatures have less defined shapes than the normal creatures they resemble. As as result, it is more difficult to score crippling or killing blows against them. A gelatinous creature:
-Cannot be flanked
-Takes 1d6 less damage from a successful sneak attack.
-Takes one-half the additional damage dealt by a critical hit.
Saving Throw Bonuses(Ex): A gelatinous creature gains a +4 racial bonus on saves agaisnt mind-affecting effects, poison, sleep, and paralysis.
Ecology
Creations of the Demon God Juiblex, these abominations exist solely to protect and serve him. They are considered guard dogs to Juiblex, powerful creatures to protect him, but their low Intelligence prevents them from being truly useful to him. These creations are easy for him to create. It is said that with a simple concoction only Juiblex knows, he coats the Huge Chimeras and waits until they are completely engulfed, for that is when they are the most gelatinous of all. Then, he shapes them to his will, creating these six-head monstrosities, though the gelatinous concoction shrinks the size of the normally Huge Chimera into a Large one.
A little known fact, but frequently speculated upon, is that Juiblex is working on this concoction and the Chimeras to create slightly different versions. A thicker hide would be an excellent for the gelatinous Chimara, but the jelliness of the body seems to prevent such creations thus far.
Variations
A horribly variation, one only recently created, is the 'living' version of the gelatinous Chimera. Now, without knowing what that is specifically referring to, it makes absolutely no sense. However, when you see a 'living' gelatinous Chimera, you'll know EXACTLY what this refers to... well, pray to whichever Gods you must that you never are forced to witness such a horrid spectacle. No, don't just do that. Run, hide, do whatever you must to avoid the wrath of Juiblex, even if that means befriending the mold on you week-old bread.
Regenaration 5
Jelly Shot (Ex): By taking 31 damage, the 'living' Gelatinous Chimera can throw a small portion of itself as a touch attack with a 10' range increment. This portion is treated as a separate entity with it's own - for Intelligence [it is a normal Gray Ooze as found in the Monster Manual]. However, it will never attack a Gelatinous Chimera, who is, of course, immune to the acidic damage of the jelly's attack.
CR: +2.
Chimera: Monster Manual
Fiendish Template: Monster Manual
Gelatinous Template: Savage Species
Multiheaded Template: Savage Species