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"The Lost Dinosaur"
Season/Series: 21
Number in season: 6a
Original Airdate: United States February 14, 2018[1]
United Kingdom June 11, 2020[2]
Written by: Jessica Carleton
Storyboard by: Cilbur Rocha
"Take a Hike, Molly"
"The Princess Problem"
Read transcript

"The Lost Dinosaur" is the first half of the sixth episode in the twenty-first season of Arthur.


It is difficult to lose a dinosaur... but Rapty is missing! Can Bud Compson be brave without his imaginary friend? 


Bud introduces the viewers to Rapty, his stuffed dinosaur. On his first day of preschool, Rapty encouraged him to make friends with the other kids, and helped him get through his first haircut. Bud says that Rapty is the bravest dinosaur in the world, only for him to get scared by ants.

The Lost Dinosaur

Bud searches for Rapty in his messy room. Ladonna enters Bud's room and tells him to clean it, finding a moldy orange. Bud visits D.W., who tells him not to worry and that she eventually finds whatever she loses. Bud worries about failing a job interview after having lost Rapty for 20 years, and D.W. tells him to look in places he wouldn't expect to find Rapty.

Bud's father helps him search for Rapty at night, but then makes him go to bed. Bud is unable to sleep and wakes up Ladonna, who gives him Platy, her old stuffed platypus, so he can get to sleep. Bud imagines Platy being alive, and when Platy hears that Rapty is lost, he starts crying. Bud is kept awake by Platy's talking.

In the morning, Bud gives Platy back to Ladonna, but then decides to keep him for a dentist appointment. Bud tells Platy about the dentist, who starts worrying. He talks with D.W., afraid that he will not find Rapty before his dentist visit. Meanwhile, Platy annoys Nadine, who tells D.W. to ask Bud to leave.

Bud asks Platy what he would do to relax him for the dentist visit. Platy says, "It won't be so bad when the dentist removes all your teeth!" and Bud returns Platy to Ladonna, saying that Platy is unhelpful. Before leaving for his appointment, Bud feels guilty and goes to apologize to Platy. Platy tells him that he is brave and Bud realizes that he has been braver since he lost Rapty, not being scared of the dentist.

Bud goes to the dentist without Platy, having done well, and Ladonna then presents him with Rapty when he gets home. Bud tells Platy and Rapty about his dental appointment, giving Platy the toothbrush he got from the dentist.

That night, Rapty reveals that he was in the washing machine. He and Bud go to bed while Ladonna and Platy enter the room. Ladonna is happy that Rapty is back with Bud, while Platy is glad that he does not have to be with Bud anymore.






  • An Elwood City Grebes baseball cap can be seen among the objects in Bud's room.
  • A picture of Marc Brown, as he appears on the show, is on the wall in the barber shop. Marc Brown also stands in the employment office.
  • This is the last episode to show the Compsons' house until "When Duty Calls."

Episode connections

  • Bud goes to the dentist. This could be the same dental appointment that Rufus refers to in "Francine & the Soccer Spy."
  • At the end of “Lost!”, D.W. tells Arthur never to get lost again. Bud says almost the same thing to Rapty.


Main article: The Lost Dinosaur/Gallery


External links