Basic Trope: An otherworldly character appears in a work to make people laugh.
Straight: Bobdoz from the planet Tropetar amuses the audience when he mistakes parking meters for robots.
Bobdoz dates parking meters and plans to marry one.
Every alien on story happens to have a thing for comedy. Some of them are rather clever and get good amounts of laughs, but others are just Pungeon Masters that cause groaning (in-story and on the audience) whenever they show up.
Downplayed: Bobdoz has a bad habit of pulling doors marked "push".
Justified: Bobdoz's behavior is normal from where he comes from.
Bobdoz acts in a perfectly normal way, but everyone laughs anyway.
Bobdoz acts in a very amusingly weird manner, but everyone acts as if it's ordinary.
Alternatively, Bobdoz is expertly familiar with human customs and technology, but uses Obfuscating Stupidity so that humans consider him a harmless fool. They are thus unprepared when he launches his Alien Invasion from within.
...Except for Alice, that finds his buffoonish antics incredibly irritating, and unintentionally becoming a comedic duo with him.
...the invasion is hilarious.
Zig Zagged: In light-hearted or breather episodes, Bobdoz is The Klutz who doesn't know one end of a toaster from the other and is generally treated as the series comic relief. In a more serious episode however, he no longer has trouble with human technology and becomes serious and competent. Then when the action is over he goes back to being the technologically challenged comic relief again.
Averted: Despite their unfamiliarity to Earth's customs, no alien on this story acts in a particularly wacky manner.
Enforced: "The Bobdoz Show" is created to fill a hole in the network's programming.
Lampshaded: "Bobdoz has been living with us for months now. Why is he still having trouble telling the radio and the toaster oven apart?"
Invoked: It turns out Bobdoz is rather savvy regarding Earth's social norms and culture, but he prefers to act as wacky as possible because, being a former habitant from a planet where almost no one has humor sense, he likes making people laugh.
A Con Man targets aliens, knowing them to be naive and clueless.
Bobdoz is given a reality TV show.
Defied: When Bobdoz first meets Alice, she gives him a crash course in Earth cultures and customs.
Discussed: "Bobodoz may be an alien, but he's not as weird as you might expect. In fact, he seems normal to me."
Alice: "You know, I was watching this show where there's this alien called Bobdoz. He's really friendly, but doesn't have a clue how human technology works."
Bob: (Fighting off a group of human eating aliens who have managed to turn a toaster into a death-ray) "Great, why can't our alien invaders be like the ones on your show?
Deconstructed: Bobdoz's amusingly weird antics attract the attention of the authorities.
Reconstructed: ...who use his advanced alien technology to spread his amusingly weird antics around the world.