Dennis cares for a dog named Charlie who wins a prize for his painting!

Dennis learns Opie might leave because his bees have no honey. Dennis sprays prfume on Mr. Willison's flowers.

Dennis gets what he thinks is a hampster which turns out to be a gopher that escapes from his cage and almost ruins Mr. Wilson's yard.

Mr. Wilson has a stock certificate worth $500. He hides it in his Phone book, however when Dennis brings him in his new phone book Mr. Wilson goes crazy and ends up going to the warehouse where all the old phonebooks are taken to look for his old phone book because he thinks the stock is still in it.

Dennis is very upset because he doesn't know how to whistle, So he spends all day trying to learn how.

Dennis writes a composition for school on his best friend and he chooses Mr. Wilson to write about.

Dennis attempts to buy a fishing rod for his dad and tries to purchase it with a $50.00 Confederate bill.

Dennis overhears Mr. Wilson saying that he wishes he had his racoon coat back, so he gives the story to the newspaper and so all day people are bringing Mr. Wilson racoon coats.

Dennis, Mr. Wilson, Mr. Mitchell camp out as pioneers to prove to Mr. Krinkie that they can live of the land like the pioneers.

Dennis decides to give Mr. Wilson his own father's day, Which in the end turns out for the best when Dennis gets Mr. Wilson out of a lawsuit concerning his dog, Fremont.

Mr. Wilson accidentlly gets a space helmet that belongs to Dennis stuck on his head.

Mr. Wilson wants to represent Scotland for Dennis' School

The school test scores mistake Dennis as a genius.

Mr. Wilson tricks Dennis into taking a silver coin that says GOOD LUCK and a horseshoe on it instead of 50 cents that he owes him for cutting his lawn. Mrs. Wilson is very angry with him about it. So, she and Alice start a scheme of their own by making lucky things happen to Dennis all day. Mr. Wilson soon starts to believe that the coin was lucky after all and is sorry he ever let it go. He then realizes that it was all a charade to teach him a lesson.

Dennis, Henry and Mr. Wilson go out in the woods and cut down a big Christmas tree which ends up getting almost destroyed by the time they get it home.

Dennis opens a bank account at the bank of where Mr. Wilson works at and causes a lot of chaos at the bank.

Mr. Wilson's Uncle comes to visit him and convinces him that he isn't in shape, so he starts a physical fitness program and forces Mr. Mitchell and Mr. Wilson to be in it.

Mr. Wilson gets his wallet taken by a pick pocket, So Dennis and Tommy try to find the crook for the police.

Dennis does a documentary film of the town for a school project with Mr. Wilson's help.

Mr. Wilson takes Dennis and his friends up to the lake and back in an old car. Mr. Wilson then gets elected president of the Horseless Carriage Club.

Dennis helps Mr. Wilson's Uncle Ned plant flower bulbs in his yard in order to get out of playing house with Margaret Wade.

Dennis wants to join an older boys club, but in order to do so he has to take an initiation.

Dennis gets a job for a day delivering Circulars for Mrs. Elkins. But, When he swaps territories with another kid, he gets blamed for throwing the circulars in a trash can.

Dennis gets a new Principal, Mr. Spivey who is very strict at his school. Mr. Spivey and Dennis get off on the wrong foot at first However, Johnny Brady takes note of that and because he wants to be on the pitcher on the school baseball team. So, he sets Dennis up by drawling a picture on the back of his paper making fun Mr. Spivey's height. When Mr. Spivey finds it he naturally assumes Dennis is the one that drew it so he punishes Dennis by kicking him off the baseball team and keeping him after school. As the news travels Mr. Wilson, Mr. Quigley and Mr. Finch all go to the school a few minutes apart and talk to Mr. Spivey each claiming to be Henry Mitchell to stand up for Dennis. Mr. Spivey gets confused but soon realizes he misjudged Dennis and ends up apologizing and putting Dennis back on the school baseball team.

Mr. Wilson hangs out and plays with Dennis and his friends the whole day to gather information for a magazine article of what young children do in this day and age.

Mr. Wilson tells Dennis he isn't feeling well to get Dennis to leave him alone and then Dennis tells the whole neighborhood, So they all think that Mr. Wilson is very sick.

Dennis becomes confused about love when he hears his parents and Mr.& Mrs. Wilson argue with one another.

Dennis is appointed by the Mayor to go to Washington and ask the Senater to pass a bill for a national Forest.

Dennis accidentally ties an important note that belongs to Mr. Wilson on a pigeon, so Mr. Wilson, Henry, Tommy and Dennis go to where the pigeons roost at night at a spooky house to try and get the note back and end up in the middle of a collage fraternity initiation meant for new fraternity members. After a bunch of twists and turns they find the pigeon with the note tied on it.

Mr. Wilson attempts to dye his hair in order to look younger for an actress he is interviewing for her life story. However, the dye made his hair look worse and so he cons Henry into taking his place which end in a bunch of tangled webs.

Dennis and his friends start up a laundry business and clean Mr. Wilson's tuxedo, only Dennis gets Mr. Wilson's tuxedo mixed up with other peoples.

Mr. Wilson is planning to take Mrs. Wilson to Hawaii. But when Mr. Wilson has the plane tickets mailed to the Mitchell's, Alice thinks Henry is taking her to Hawaii.