The dupes from left to right: Dupe 2, Dupe 3, Dupe 4, Dupe 5, Dupe 6

Duplicates number 2 through 6 of Calvin were created when Calvin used the Duplicator to create a duplicate of himself to do all his chores and schoolwork. This backfired, however, as the duplicate made four more of himself (he would've made more, but the duplicator overheated). The duplicates apparently assigned numbers to themselves, as they all looked identical to one another. Later, Calvin made a deal saying each one only had to go to school one day of each week and "none of us will be the wiser". They each get in trouble every time they go. Calvin stops them by tricking them under the duplicator, turning it into a Transmogrifier, and transmogrifying them into worms. When Hobbes questions this, Calvin responds that he didn't want them to be unhappy. The transmogrified duplicates were never heard from again, although the incident of the duplicates has been referred to. They are the main antagonists of the title storyline for Scientific Progress Goes "Boink". 

In Calvin and Hobbes, they were the third main antagonists. In the movie, they were turned back into humans from worms by Dark Calvin. They all have different personalities, but they all enjoy flipping girl's skirts, including Susie Derkins', Ginger's, and Avery Elmhurst's.

Duplicate #2

Duplicate number two was the first duplicate of Calvin. After Calvin told him to do a lot of work, the Duplicate ran away to play outside (since he possessed all the qualities of the original), but before he could, Calvin's mom sent him to Calvin's room, thinking that he was the real Calvin. When he was in Calvin's room, he created more duplicates. It is unknown how this was possible, or who pushed the button that created Duplicate #3, as Duplicate #2 must have been inside the box at the time. Duplicate number two was the first one of the Duplicates to go to school. When he then turned back into a human he was the only serious one and wanted to kill Calvin.

Duplicate #3

Duplicate number three rarely had any major appearances, because, when he was with all of the other Duplicates, it was unknown which one he was. It is unknown if he went to school. When he was a human again he was more lazy and fat, perhaps a reference to Garfield.

Duplicate #4

Duplicate number four first appeared with the rest of the Duplicates.  Duplicate number four was the third of the Duplicates to go to school. He was also sent to the principal's office, like Duplicate number two and Duplicate number five. It is unknown why he was sent to Principal Spittle's office, but it is known that he took some chalk. When he was a human he was scared of almost everything.

Duplicate #5

Duplicate number five was the second of the Duplicates to go to school. While in school, he is asked to demonstrate a math problem given yesterday. He tries to explain to Miss Wormwood that it wasn't him in school yesterday, but Duplicate number two, but is not believed and sent to the principal's office. When he turned back into a human he was very smart.

Duplicate #6

Duplicate number six was the only who rarely seen in any comics, but in Calvin and Hobbes, when he was turned back into a human he was wild and crazy.

Other Duplicates

In Calvin and Hobbes 3, Calvin brought a button similar to the Time Pauser. When he pressed it, it brought a surprise attack from 40 other duplicates to attack the Stalker I, each with two in a spaceship. It is unknown if these duplicates had equal or separate personality. Most of them have the personality of Dupe 5.

Calvin clone and Hobbes clone

In Calvin and Hobbes IV:Which Way Is Where? in The Greasy Spoon Scene,Calvin and Hobbes duplicate themselves in the restroom,and the duplicates go on the trip.

Duplicates 7,8,9,and 10

Duplicate 7

Dupllcate 7 is an exclusive character in NMMacc18's Calvin and Hobbes saga. He is one of the sinister masterminds behind the plans,the other being Dr.Scientist. He is voiced by Ralph Macchio.

Duplicate 8

After Duplicate 7 cloned himself,his clone turned out to be a tough duplicate with super strength,dubbed Duplicate 8. He is voiced by Ice Cube.

Duplicate 9

Duplicate 8 cloned himself,and came out two versions of him. Duplicate 9 was the meek one out of all the duplicates. He is voiced by Michael Cera,using Robin's voice from The Lego Batman Movie.

Duplicate 10

Duplicate 10 was the last of the duplicates to be created. He had the ability to teleport. He is voiced by Seth MacFarlane.