This creature appears to be a bright pink ooze speckled with spots of green, yellow, and blue. Scattered across the body of the ooze are small spiracles through which it apparently breathes.
Source: Tome of Horror IV Pathfinder
Jolly Jellies are psychic vampire that feed on emotions. The mere presence of a Jolly Jelly causes creatures to become sullen. Victims of the Jelly tends to erupt into violence as all traces of joy is drained from their body. The Jolly Jelly receives all it's nourishment from feeding on victims emotions. They can go for months before meals.
Jolly Jellies are most active at sunrise and sunset. They hide dormant in underground lairs and hollow logs waiting for their prey. They lack the acid most oozes possess and tend to attack with their pseudopods. Once close to death they release their pheromones. The buildup of positive emotions can cause adventurers to break out in uncontrollable laughter.
Combat: Jolly Jellies are a Challenge Rating 5 Medium Oooze. They have three slam attacks dealing 1d6+2 damage. They have a very low armor class of 10 and decent hit points that average around 63.
-Aura of Gloom: Any living creature within 30ft of the Jelly must make a DC 14 will save or take 2 points of charisma damage. Each round that adventurer is within 30ft they must make another save. If the victim takes 6 points of charisma damage they come under a rage effect.
-Pheromones: Once per day as a swift action they Jolly Jelly can release it pheromones in a 20ft radius. This is the distilled positive emotions it has stored. All creatures in that radius must make DC 19 fort save or fall under the effect of hideous laughter for 2d4 rounds. While you are laughing you fall prone and can do nothing but chuckle.
-Traits: The Jolly Jolly has the Ooze type, blindsight 60ft, and immune to fire.
The Jolly Jelly is an interesting creature. Having multiple Jellies can cause havoc on party members who decided to dump their charisma. If you are reduced to zero charisma you can't do anything. Also making multiple Will saves each round targets a fighter weak save. The pheromones is a nice last resort ability to send the party in a fit of laughter while the ooze slithers away.