|Chimpan-Zzzz's is a special gas used to put monkeys to sleep. The gas was purchased by Sgt. Nunez in order to force Troy's pet monkey Annie's Boobs out of it's hiding place in the school's ventilation system. The gas proved to be harmful to humans causing hallucinations and possibly worse psychological damage if exposed to it for too long. Its first appearance was in the Season Three episode "Biology 101".|
In the study group's third year at Greendale, Dean Pelton decided that he would have a more serious year without any of the shenanigans that occurred in the previous one. He summoned campus security led by Sgt. Nunez to his office and informed them their main priority at the start of the semester would be getting rid of the monkey who had made the school's air vents his home. After being pressed for ideas on how to deal with the assignment, Nunez suggested they use some kind of monkey knock-out gas. The Dean approved and later Nunez and his men purchased a tank of "Chimpan-Zzz's".
They systematically flooded the school's ventilation system with the gas, wheeling the container to various air vents. However, they were unsuccessful in their attempts to "smoke" out the monkey with it. Instead they ended up dosing Jeff Winger and Ben Chang who had been inside the air vents at the same time they released the gas into it. The gas induced major hallucinations in both victims; Chang was exposed to it the most and it's hinted that this caused him to become more unstable. Nunez later presented the invoice for the gas to Dean Pelton but was told he couldn't pay for it - or their salaries for that matter - due to recent budget cuts ("Biology 101").
When the study group re-enrolled for a fifth year together at Greendale, they joined a special committee dedicated to improving the school. One day a few of them were tricked into volunteering to clean up a storage room in the East Hall. Inside the room and off to one corner, several empty containers of Chimpan-Zzzz's can clearly be seen ("VCR Maintenance and Educational Publishing").