In "The Last Roundup", we finally get to hear "Derpy Hooves". She's klutzy and has a "idiot" voice. More specifically, she has the same type of voice as Ed from "Ed, Edd, and Eddy". She is wildly popular in fandom because of an animation mistake in her eyes, and then fans liked her, giving her the name. This episode had the name confirmed.

Now, of course, some people are saying her portrayal is ableist.
More specifically, the eyes, combined with her "stupid" voice, general klutziness, and now canon-confirmed name resemble a stereotype.
1. The eyes. The "DERP" meme (more on that later), has a number of images associated with eyes like that. While they resemble those which may be found by mentally challenged individuals, this is not their specific intent. It's just someone's eyes doing silly things.
2, 3. Derpy is, canonically, kind of a klutz. She dropped several standard cartoon items out of a flying moving truck in an earlier episode. Her "beta" name was Ditzy Doo. The voice is entirely consistent with her characterization thus far, and in the episode in question, she basically destroys Town Hall while putting up part decorations. There's a difference between "not too bright" and "mental impairment".
4. The meme originated from South Park character "Mr. Derp", a character who provides, in-canon, silly, childish, slapstick humor. Hence the term coming to mean "insert something dumb here".
5. Complaining about something that "resembles a stereotype" is mealy-mouthed nonsense. Say it "resembles a stereotype and may perpetuate it", or "may be mistaken for one", but it's usually presumptuous to go "it resembles a stereotype and is an example of it being used in a malicious manner". Yes, I know about unconscious bigotry.
Frankly, if some kid discriminates against someone because a fictional pegasus is kind of an idiot, they have bigger problems. It's like blaming violence on GTA, or teen sex on Rock and Roll music, except even more ridiculous.
Yes, I understand the irony of me getting angry at people on the Internet for getting angry about pointless things.
Screw it. I'm going to find some fried chicken and a watermelon and a basketball tomorrow, just because.

Now, of course, some people are saying her portrayal is ableist.
More specifically, the eyes, combined with her "stupid" voice, general klutziness, and now canon-confirmed name resemble a stereotype.
1. The eyes. The "DERP" meme (more on that later), has a number of images associated with eyes like that. While they resemble those which may be found by mentally challenged individuals, this is not their specific intent. It's just someone's eyes doing silly things.
2, 3. Derpy is, canonically, kind of a klutz. She dropped several standard cartoon items out of a flying moving truck in an earlier episode. Her "beta" name was Ditzy Doo. The voice is entirely consistent with her characterization thus far, and in the episode in question, she basically destroys Town Hall while putting up part decorations. There's a difference between "not too bright" and "mental impairment".
4. The meme originated from South Park character "Mr. Derp", a character who provides, in-canon, silly, childish, slapstick humor. Hence the term coming to mean "insert something dumb here".
5. Complaining about something that "resembles a stereotype" is mealy-mouthed nonsense. Say it "resembles a stereotype and may perpetuate it", or "may be mistaken for one", but it's usually presumptuous to go "it resembles a stereotype and is an example of it being used in a malicious manner". Yes, I know about unconscious bigotry.
Frankly, if some kid discriminates against someone because a fictional pegasus is kind of an idiot, they have bigger problems. It's like blaming violence on GTA, or teen sex on Rock and Roll music, except even more ridiculous.
Yes, I understand the irony of me getting angry at people on the Internet for getting angry about pointless things.
Screw it. I'm going to find some fried chicken and a watermelon and a basketball tomorrow, just because.