Information is definitely out-dated, and you shouldn't really take it to heart.
The image is recreated to show what it could of looked like.
The MLG Cannon (standing for Major League Gaming Cannon) was one of the first three "attachments" in R2DA.
It served no purpose at all other than to serve the purpose of testing the attachment system out.
Theoretically, this would add a cannon to the MP5 and allow the user to shoot grenades instead of bullets.
Attachments weren't initially considered to be mass-produced by manufacturers. Survivors were upset by this decision.
Being rather passive-aggressive, survivors dreamt up some things they would've liked to put on their guns and the MLG Cannon would become one of the more popular ones. Ultimately, the sarcastic tones got to the manufacturers and they went to work.
- One of the three weird Attachments for the MP5, the others being the Mega Knife and Epic Scope.
- This was misspelled as "MLG Canon" in-game.