This is a vaguely humanoid figure made up of a cloud of spooky levitating pool balls. You spend a few seconds trying to figure out the best place to kick it, but to no avail. It hovers toward you, eerily clicking and clacking.
Hit Message(s):
It hits you on either side of your head with a pair of 4-balls. If only it had yelled "Fore!" first to give you some warning. Ouch! Eek! Ow!
It hits you in the <head> with a 1-ball. Ouch! Ooh! Eek!
It performs an elaborate internal bankshot, and a 6-ball rockets at you. It's too bad you didn't have a pocket in your <head> -- that wouldn't have hurt nearly as much. Oof! Ooh! Ouch!
Critical Hit Message:
It slides two balls under each of your feet, which cause you to slip and fall down. Then it hits you in the <head> with a 1-ball, the <head> with a 3-ball, the <head> with a 5-ball, and the <head> with a 7-ball. What an odd combination. Ugh! Ow! Ooh!
Miss Message(s):
It slings three balls at you, but you quickly catch them, juggle them for a while, and throw them back.
It hurls a 1-ball at you, but the ball is too yellow to get near enough to hurt you.
It slings a 6-ball at you, but you duck behind the pool table and it ricochets harmlessly off of the rail.
Fumble Message:
The pooltergeist floats toward you, but accidentally collides with a rack of pool cues. Hilarity ensues. For you, not for the pooltergeist. (FUMBLE!)
There are two distinct versions of this monster; one is a normal encounter dropping balls 1-9, while the other is an ultra-rare which drops only the 17-ball. The ultra rare version has this animated picture:
The 9-ball is unaffected by item drop rate increasers.
History
The 9-ball was added as an item drop on Jan 1, 2022, with the removal of its previous clover-basedsource.
References
A slang term for testicles is "balls", which can be a very painful part of the body to have kicked. This apparition is nothing but balls, hence the joke about figuring out the best place to kick it.
Pooltergeist is also a play on poltergeist, a ghost which manifests itself by moving around inanimate objects - like pool balls, for instance.
"Fore!" is a warning called out in golf when a ball is hit dangerously close to another golfer.
The color of the 1-ball in a traditional billiards set is yellow, which is also slang for being cowardly. Hence the miss message.
The odd combination in the critical hit message is the sequence of the odd numbered balls in pool.