The first real showing of an "alien" was in the episode called "Little Green Men." It was the first episode of the second season.
The names of the aliens are "Kang" and "Kodos". They first made their appearance in "Treehouse of Horror" in season 2. They have appeared in every Treehouse of Horror epsisode since then.
No. Since aliens do not appear to actually exist (somebody has to be the first form of intelligent life in the Universe, no reason to think it is not us), they cannot be gotten to do anything.
Season 3
Since aliens do not appear to actually exist, and are probably not criminals if they do exist, there is no way. Someone has to be the first form of intelligent life in the universe, and there is no reason to think it is not us.
"Towelie"(season 5, espisode 8)
Season 2, episode 3.
As many as you care to imagine. Aliens appear to be purely imaginary. Someone has to be the first form of intelligent life, it may well be us. ------------------------------------------- 51 nnnnnoooooooooooobbbbbb
Season 2, Episode 5,
Discord does not appear in season 1. His first appearance is in the season 2 premier.
he first appear as a patient back in season 3 and appears as a "ghost" during season 5
Season 4 episode 1
in the first season, don't know what episode