The provided text is a countdown of the saddest moments in kid shows, from number 20 to number 1. The moments range from a kitten getting turned into cookies in "Married Melodies Feed the Kitty" to Mr. Rogers saying goodbye in the final episode of "Mister Rogers' Neighborhood". Other notable mentions include the death of Rebecca the elephant in "The Wild Thornberrys", the Ice King's backstory in "Adventure Time", and Chuckie learning about his deceased mother in "Rugrats".
Here are the key facts extracted from the text:
1. The episode "Married Melodies" from the show "CatDog" features a bulldog named Mark befriend a small kitten that he tries to hide from his owner, but the kitten eventually ends up in an electric mixer.
2. In the episode "The World of David the Gnome", the main characters David and Lisa must travel to the Mountains of Beyond because they are approaching the age of 400, after which gnomes die.
3. The episode "The Great Parent Mystery" from the show "CatDog" features the two main characters searching for their parents, but they eventually discover that they were raised by a different set of parents.
4. The episode "I Remember You" from the show "Adventure Time" explores the relationship between the Ice King and Marceline the Vampire Queen, and reveals that the Ice King used to take care of Marceline as a young girl.
5. The episode "The Man Who Has Everything" from the show "Justice League Unlimited" features Superman trapped in a dream where his home planet Krypton was not destroyed, and he lives with a wife and son.
6. The episode "Cookie Chomper the Third" from the show "Alvin and the Chipmunks" features the Chipmunks finding a stray cat that they try to keep, but the cat eventually gets hit by a car and dies.
7. The episode "Roses Scabbard" from the show "Steven Universe" features Pearl mourning the loss of Rose Quartz, and reveals that Pearl and Rose had a deep and close relationship.
8. The episode "Bye-Bye Butterfree" from the show "Pokémon" features Ash's Butterfree leaving him to be with its mate.
9. The episode "Gary Takes a Bath" from the show "SpongeBob SquarePants" features Gary running away from SpongeBob after being neglected.
10. The episode "Rebecca Dies" from the show "The Wild Thornberrys" features a young elephant named Rebecca dying in front of Eliza and her father Nigel.
11. The final episode of the show "Dinosaurs" features the Sinclair family preparing for their final night together as the world around them freezes.
12. The episode "mr. Hooper's Death" from the show "Sesame Street" features the characters dealing with the death of their friend mr. Hooper.
13. The episode "Courage's Parents" from the show "Courage the Cowardly Dog" features Courage's backstory and how he ended up with Muriel and Eustace.
14. The episode "The Song of the Dead" from the show "Avatar: The Last Airbender" features a character named Jet singing a song about his deceased son.
15. The episode "Helga on the Couch" from the show "Hey Arnold!" features Helga talking to a school psychologist about her home life and her feelings towards Arnold.
16. The episode "Arnold's Christmas" from the show "Hey Arnold!" features Arnold trying to find out why his teacher mr. Lewin is always sad at Christmas time, and learning about mr. Lewin's daughter who he gave up during the Vietnam War.
17. The episode "Mother's Day" from the show "Rugrats" features the babies trying to find Chuckie a new mom, and Chuckie learning about his deceased mother.
18. The final episode of the show "Mr. Rogers' Neighborhood" features mr. Rogers saying goodbye to his viewers and announcing his retirement due to his diagnosis with stomach cancer.