Mr. Ambassador,
Whilst endeavoring to locate your missing bags' coordinates, I did attempt to interrogate the BPB Squatch. He proved to be very uncooperative. After numerous attempts to communicate were unsuccessful, I decided a more direct approach was in order, and, not having the foresight to bring my portable waterboarding equipment with me, thought perhaps a thorough trouncing with a starter ball might loosen him up a bit.
Unfortunately, he still refused to talk, nor was I able to confirm the sound you described. Research will continue.
Doc :)