Think about the last time you heard a movie villain laugh.
It's a very specific, deranged sound. Maniacal laughter usually follows something like the Joker blowing up a building or Darth Vader believing he's won, but I think it's pretty rare to hear in real life. After all, few of us know true villains.
When a cockatoo made a mess, though, it decided to pull out its best impressions, and something hilarious and creepy came out.