This creature appears to be a yellowish-brown amoeba.
Mustard Jelly CR 7
XP 3,200
N Large ooze
hp 105 (10d8+60)
Fort +9, Ref +3, Will +3
Melee slam +9 (2d4+3 plus 1d4 acid)
Space 10 ft.; Reach 5 ft.
Base Atk +7; CMB +10; CMD 20 (can’t be tripped)
Feats Cleave, Power Attack, Skill Focus (Perception), Vital Strike, Weapon Focus (slam)
Environment temperate marshes
Organization solitary
Treasure none
Mustard jelly appears to be a yellowish-brown form of the ochre jelly and is thought to be a distant relative of said creature. However, the mustard jelly is far more dangerous than its supposed relative because it is intelligent.
The mustard jelly gives off a faint odor of mustard plants to a range of 20 feet. Though it possesses intelligence, a mustard jelly cannot speak.
A mustard jelly attacks by forming a pseudopod from its body and either slashing or enveloping its foes. Mustard jellies prefer to attack from ambush or where they have the upper hand on an opponent. If combat goes against a mustard jelly, it does not hesitate to flee, though often it uses this tactic to lure unsuspecting foes in closer.
A mustard jelly’s natural weapons are treated as magic weapons for the purpose of overcoming damage reduction.
Mustard Jelly from the Tome of Horrors Complete, Copyright 2011, Necromancer Games, Inc., published and distributed by Frog God Games; Author Scott Greene, based on original material by Gary Gygax.