Exasperating Ooze

From publisher blurb: Wandering through forests, or in the deeps, pretty much anywhere adventurers can be found, the Exasperating Ooze is a strange, blob like ooze. Ranging in color from dull orange to dull red, with black vein like structures, it slowly moves through any terrain. What it survives on, where it comes from and even why it exists are all questions that have not satisfactorily been answered. Current speculation leans towards a minor deity, displeased with its followers who sought only to advance themselves. Inside every Exasperating Ooze, directly at its center, are 2,000 GP worth of gold coins, just visible to anyone observing the Ooze. What gives this ooze its name is the inability to actually affect it, gain any treasure from it and learn from the experience. With seemingly every hit, this amorphous blob grows larger and as it grows larger and angrier, it becomes worth more XP to the party and becomes harder to kill, making it a more tempting target for the party to attack, making it worth more to the party and making it harder to kill. A creature to confound your experience goggle wearing party.