dacoycoy
A loud, obnoxious person who cackles like a madman. They laugh so hard they might fall over, and they don't care if anyone else is having a bad day.
He laughed so loud in the library that the librarian gave him a time-out.
She cackled during my presentation like I was telling a joke about her ex.
He laughed when I tripped over my own feet, then laughed harder when I fell.