F.L.A.R.G. is a holiday that is celebrated by the Yugopotamians or else their appendix will explode, which is powerful enough to take out a whole city. However, the holiday is never celebrated on their home planet because on the fifth day of F.L.A.R.G., the Yugopotamians say goodbye and blow up the planet that they celebrate it on. F.L.A.R.G. stands for a series of events that are repulsive and unappealing to humans, but very stimulating to Yugopotamians. In addition to the events, the Yugopotamians also toast manure, drinking the contents happily.
Days of F.L.A.R.G.
There are five days of F.L.A.R.G. and each letter represents a different day in F.L.A.R.G.
The F in F.L.A.R.G. stands for Fart. The Yugopotamians basically let out a big, rank fart that is so smelly that it can make birds die.
The L stands for Lie. Mark lied to Timmy and implied the L stood for love, giving him a love orb which Timmy thought would get Trixie to like him. Timmy realizes that he was tricked when Trixie screamed for security when Timmy asked her for a kiss.
The A in F.L.A.R.G. stands for Amnesia, and the Yugopotamian's host gets amnesia, usually after they do something incredible or fun. For example, Mark made Timmy forget about an awesome party where he sang with Chip Skylark, ate buckets of ice cream with his friends Chester and A.J., and even got Trixie to like him. Unbuttoning his shirt, Timmy also realizes that he has a tattoo of the name "Carly" on his chest.
The R in F.L.A.R.G. stands for Ranksgiving. On Ranksgiving, the Yugopotamians stuff their faces with delicious Earth food (which is disgusting to the Yugopotamians) causing them to vomit the contents up onto their host (which happened to be Timmy for Mark.)
The G in F.L.A.R.G. stands for Goodbye. Not only do the Yugopotamians say goodbye to F.L.A.R.G., but also to the planet that they celebrated it on. When Mark celebrated F.L.A.R.G. on Earth, he intended to blow it up with a giant missile at first, but Timmy convinces him that he can not because Earth is his home planet now, causing him to redirect the missile to Fairy World.
Now you see why F.L.A.R.G. is never celebrated at the alien's homeworld.