Fanboy and Chum Chum

Note: Do not add the "Average Characters" category, or change the "Why They Don't Deserve To Show Their Underwear (Why They Suck)" to "Bad Qualities", or the "Redeeming Qualities" to "Good Qualities", respectively, as these two characters are not considered average despite their fanbases and Anyone who persists will start an edit war. Fanboy and Chum Chum are the titular protagonists of the critically-panned 2009 Nickelodeon series, Fanboy & Chum Chum.

Why They Don't Deserve To Show Their Underwear

 * 1) Their characters are basically little more than pale rip-offs of both SpongeBob SquarePants and Patrick Star along two superheroes, Mermaid Man and Barnacle Boy from SpongeBob SquarePants, with the combined worst traits of both characters and with none of their intelligence, likability and charm, so much to the point that it makes both SpongeBob and Patrick's respective Season 6-8 incarnations look like way more likable, mature, comedic, intelligent and less annoying characters. In fact, if you take away everything likable from both SpongeBob and Patrick, you get both Fanboy and Chum Chum in a nutshell.
 * 2) They are poor parodies of Batman and Robin from DC comics.
 * 3) Their names are downright laughable.
 * 4) They're a generic comic relief duo who go on wacky and crazy adventures.
 * 5) Their voices are really loud, high-pitched and squealy, not helping is the fact that they often scream loudly most of the time.
 * 6) They provide way too much toilet and gross-out humor.
 * 7) * They have a gross habit of sticking out their underwear in front of other people.
 * 8) * As said in the intro, they have said "We don't care if you stare, I mean look at our underwear!"
 * 9) * They have swapped noses in the infamous episode "Pick A Nose".
 * 10) * Chum Chum got his nose rubbed by Mr. Mufflin's smelly foot.
 * 11) * Fanboy got his head stuck in a toilet.
 * 12) Their character designs are laughably bad. They look more like monkeys than humans and even look like they were stolen from other medias.
 * 13) They always annoy and pick on Kyle and Lenny every time they encounter them. What's worse is that they usually never get their comeuppances. Meaning that they're Karma Houdinis.
 * 14) They cry over things that aren’t a big deal whatsoever, like Fanboy when he forgot to give Chum Chum a present for his birthday.
 * 15) Despite the two often dressed up as superheroes, they barely ever act like actual superheroes.
 * 16) They have made Kyle float in the air after forcing him to chew bubble gum and they say "bubble" three times.

Redeeming Qualities

 * 1) They did get a bit better in season 2, though not by much.
 * 2) Their friendship is charming at the times.
 * 3) Their occasional action scenes are really fun to watch.
 * 4) Some of their jokes are admittedly funny.

Trivia

 * They became internet memes.