The adventures of billionaire Scrooge McDuck and his nephews Huey, Dewey and Louie, their famous uncle Donald Duck, pilot extraordinaire Launchpad, Mrs. Beakly, Webby and Roboduck. Adventures and hidden treasures are everywhere, in their hometown Duckburg and all around the world.
This tv show contains 44 potentially triggering events.
I wouldn’t say that’s gaslighting, per say- there’s nothing Magica does that’s intended to make Lena doubt her reality, although she does abuse her horribly in pretty much every other possible way
When Lena was under Magica's control, Magica would sometimes possess her in a way that makes her eyes and mouth ooze black sludge. In "The Forbidden Fountain of the Foreverglades", Ponce De Leon dies by rapidly aging while drowning.
*SPOILERS* Technically Webby is an abducted as an infant clone of Scrooge, but considering how FOWL wanted to use her and how loving her family is now, this is absolutely a good thing.
(SPOILERS) Lena, one of the secondary characters, a fifteen year old girl, is "killed" and turned into a shadow by a villain in the first season finale. The same villain also turns Webby (a thirteen year old) into a doll and disintegrates her in an earlier episode, though this is all just a dream. Overall, there are no permanent child deaths.
For most of the first season, Della Duck's fate is left up in the air until "The Last Crash of the Sunchaser!", where after Scrooge reveals the truth of what happened to her, the boys assumed she was left to die.
There is a killer clown duck in "The Trickening". !!Minor Spoilers!! he's actually a wereduck in a costume and is on good terms with the family by the end of the episode.
Lena constantly coughs up black sludge while being possessed by DeSpell, at one point it makes a pretty gross noise, I have extreme emethophobia but it didn’t really effect me but if you fear it will effect you it’s around the ending on season one, especially in the final two episodes
There is at least one mention of Doofus being mentally ill and it is from Louie. In the episode "The Life and Crimes of Scrooge Mcduck", he says that Doofus has "a very sick mind". And the serie seem to agree with Louie but I'm not sure...
huey, who has many autistic traits and is considered autistic by most fans, is bullied for being “robotic” in the beginning of “astro boyd”. he befriends an actual robot who has similar autistic traits, and the robot boy is mistreated due to being a robot. however, huey does not let the teasing get to him and boyd ends up happy at the end of the episode.
huey has what appears to be a mental breakdown in “the most dangerous game night” which is egged on by his brother (louie does not actually intend to harm him, and gets worried for him)
Lena suffers some fairly severe PTSD from her life under Magica. This comes to a head in a season 2 episode where her fears start to directly impact her friends. They help her through it.
although it is not outright stated, the character huey has many autistic traits and could easily be seen as autistic, so the teasing he receives from his fellow boy scouts could be seen as ableist
at the end of "The Forbidden Fountain of the Foreverglades!" a character dies in a swimming pool. he dies from the rapid-aging effects of the pool, but it's similar enough that it might be upsetting. and, as mentioned in another comment, there are a few instances of attempted or fake-out drownings in other episodes.