Doug is Hamburger Boy is the second part of the eleventh episode of the third season of Nickelodeon's Doug.
Mr. Dink volunteers Doug to dress up as the big Honker Burger and talk to kids in the costume at the Honker Burger for a week. Plus he has to go to the Bluffington picnic with Patti and be the big Honker Burger without telling anyone who he is. Doug's busy weekend will be something he will have to handle all on his own.
The episode begins with the sun rising, shining the buildings of Bluffington. Doug then states voice-over that the first day of summer vacation has now elapsed, and he is seen relaxing on a lawn chair in front of his house.
Doug's Journal Entry: Dear Journal. The was the first day of summer vacation, and Skeeter and I had just uncovered an ancient Action Marty burial ground. Mr. Dink came over and said he wanted to talk to me about something. But whatever it was, he didn't want to talk about it in front of Skeeter.
During summer vacation, Doug and Skeeter dig up an action figure when Mr. Dink shows up and tells Doug that he wants to talk to him about something. At his house, he shows Doug pictures of himself dressed in a hamburger suit in his photo albums. Doug realizes that the guy in the hamburger suit waving at the cars by the Honker Burger who eventually got chased by a dog was Mr. Dink, and he and his friends were laughing at him the whole time, oblivious to his identity. Since Mr. Dink has to do business downtown, Doug reluctantly agrees to take Mr. Dink's place as the Hamburger Boy, much to his own displeasure.
At the Honker Burger, Mr. Dink has Doug promising to keep his identity a secret to others, which Doug accepts. He dresses up in the hamburger suit to talk to the kids, hoping to keep his identity clandestine. Of course, Skeeter brings Dale along with him and Dale easily recognizes Doug's identity. Luckily for Doug, Skeeter denies it. On Friday, while he is taking his break, Patti finds Doug inside the Honker Burger and asks him where he has been. As Doug realizes the long line outside, he remembers his job and begins to run out of the restaurant. But before he leaves, Patti asks if he wants to come with her and Skeeter at the picnic on Saturday at Lucky Duck Lake, to which he impulsively agrees to, later realizing that he is suppose to be the Hamburger Boy at the same picnic.
On Saturday, Doug tries to think of a way to dress up as the Hamburger Boy and attend the picnic with Patti and Skeeter. He gives out the underwater freeze tag awards and ditches the costume. He meets Patti, Skeeter, Dale, and Porkchop at the picnic area, only to remember that he has to hand out more ribbons to the kids dressed as Hamburger Boy once again. When he undresses out of the hamburger suit, he finds that Dale had taken his shorts. So Doug gets back in the hamburger costume to get Dale's attention to grab his shorts. He chases the toddler, who still has his shorts, through the forest. Subsequently, he is chased by Porkchop, who is oblivious of Doug's identity. While Skeeter and Patti are riding a canoe, Patti catches a glimpse of Doug, dressed as Hamburger Boy, running from Porkchop. As the canoe riders are watching the scene, Al and Moo fall over the canoe and into the lake. Patti jumps in to save them, and Al knocks Skeeter into the lake at an attempt to climb in the canoe. Soon, everyone else is knocked in the lake and all cry for help. Both Doug and Porkchop hop in the water to successfully save them and get them back on land.
Afterward, Doug runs into the woods and goes to Skeeter and Patti. Patti tells Doug that she figured out Doug's secret and promises him not to tell anyone about it, only for Doug to find out that Patti thinks that Doug's secret was that he couldn't swim, much to Doug's relief, as his real secret is safe from everyone.
Later on TV, the Hamburger Boy is shown on the news running away while carrying a pair of shorts, and Doug and his family, as well as Mr. Dink and Mrs. Dink, are watching it at the Funnie house. Mr. Dink says the Hamburger Boy is certainly the bravest hamburger he's ever seen. Mr. Dink then winks at Doug and Doug winks back. Patti is also shown watching the show at her house, and when she turns it off, she wonders who could be the person in the suit.