Yugopotamia is almost the complete opposite of Earth. Everything Earthlings love, Yugopotamians hate, and vice versa. Chocolate is poisonous to them, hugs burn them, healthy foods are their junk food and they are afraid of things that are happy and fun. Although the Yugopotamians can be considered war-like people, they are of little danger to the people of Earth due to them creating weapons out of things that they don't know aren't harmful to species outside of themselves (i.e. bombs made of candy). By that same token however, other more dangerous aliens have been known to threaten the Yugopotamians, such as The Gigglepies, the Boudacians, and The Darkness. One running gag is that most people from Earth who have been told about Yugopotamia call it Europe. Yugopotamia is exactly 1,000,000,001,000,000 miles away from Earth, shown when Timmy wanted to send Vicky a million million miles away and Yugopotamia happens to be "one million, one million," as stated by Cosmo in Totally Spaced Out.
The planet is covered in a very alien terrain, with strange looking plants and oddly-shaped rocks jutting out of the planet's surface. Much like the Yugopotamians, the buildings as well as some random posts sticking around are also topped with exposed brains encased in a dome of glass. The surface of Yugopotamia is colored light purple and is littered with several holes, possibly craters. The space sky also appears blood red, and several stars can be seen in the distance.
Yugopotamia and its inhabitants were first introduced in the episode, "Spaced Out", when Timmy wished for an alien monster to play with. Timmy noted that the alien was so lifelike. It turned out to be real, because Cosmo and Wanda were not so good at creating aliens, so they borrowed one. Yugopotamia was seen for the first time when Queen Jipjorrulac was pacing a building in Yugopotamia, wondering where her son was.
Yugopotamia celebrates F.L.A.R.G. every year, but they celebrate it on a planet other than theirs due to the last day of F.L.A.R.G. involving them blowing up the planet they celebrate F.L.A.R.G. on (hence why it is celebrated on somewhere else other than Yugopotamia).
Yugopotamians have a bomb for an appendix that is activated depending on the celebration of F.L.A.R.G.; if the holiday is not celebrated completely, the bombs go off. After F.L.A.R.G.'s celebration is completed, the bombs defuse themselves.
Yugopotamia was destroyed by the Darkness, but was restored after the events of Wishology since it is okay in the Season 7 episode, "Planet Poof."
Yugopotamia may be an amalgamation of the former country, Yugoslavia, and the first civilization on Earth, Mesopotamia.
The former Yugoslavia was in Europe. This may be why people (often Vicky) sometimes call it Europe.