Imustdestroyall was a prank played on Angry Grandpa by Michael. It involved Michael making a YouTube channel called "Imustdestroyall" and posting videos of a masked person saying and doing threatening things to Angry Grandpa, including video taping himself walking around in Grandpa's trailer, and even getting a knife out of the sink and taking it into Angry Grandpa's bedroom while he slept. Grandpa found out about the prank after four of them had been played, and was very angry about the fact that he thought there was a killer running around in the trailer park targeting him. In the end, his revenge costed Michael his Xbox 360. When Michael asks his dad what's his problem, Angry Grandpa replies "I don't like them, Imustdestroyall of them!" before slamming it down on the concrete driveway, crushing the console.
- In the "paranormal activity" prank, Michael suggests that the "ghost" on the trash can is actually "imustdestroyall"
- Tells bad jokes
- Eats Grandpa's candy
- Once had a companion named "Imustcombustall", but Imustdestroyall told in a video he was later "destroyed".
- At first, Angry Grandpa wanted to call the police, but later just wanted to "stay up and wait for the motherf###er"
- Supposedly hacked himself into AG's computer
- Imustdestroyall was called in the Angry Grandpa Radio disguised as another user and harrassed Angry Grandpa.