When you break Peacock's throw, often the bag she used get left behind and doesn't stop wiggling. The bag persists for as short a few seconds to as long as 30 seconds or more. I originally thought this only happens when Cerebella breaks her throw (because her throw breaks staggers opponents), but it looks like it happens with all characters. You can summon multiple bags if she tries to throw you again and it doesn't affect gameplay other than being visually distracting.
iPhone 6s running iOS 10.3.1
iPhone 6s running iOS 10.3.1