They and Boombox are friends, and have gotten along well with each other a way lot.
Episodes Suggesting a Friendship
In How It All Began, Party Hat agreed to team with Shieldy.
In A Treasured Welcome, Shieldy finds the blue tree for Party Hat.
In Unprepared To Be Scared, Party Hat is shocked at Shieldy's disappearance. Then when he sees Shieldy ghosted, he asks what happened and Shieldy asks him what happened to him.
Episodes Suggesting a Conflict
In How It All Began, when Party Hat said "I can't drive!" Shieldy said "You shouldn't be kidding me!"
In The Ever Convenient Objects' Shopping Mall, Party Hat hypers into Shieldy's face. When Party Hat asks if there is a paying limit, Shieldy says he doesn't care because he's not gonna pay.
In Go, Battle Monster!, Party Hat beat Shieldy on a match.
- Shieldy is younger, but he's more of a fan fave.