Bianca Castafiore is an
opera singer who inhabits the
Tintin universe. She shows up
everywhere, and is known for having a voice that can and does shatter nearby glass and ceramic objects. Typically, when you least expect it, there will be heard a chorus of
Ah, my beauty, past compare
These Jewels Bright I wear...
...at which point, prudent folk like Captain Haddock and Snowy dive for cover behind whatever large object is handy. There is a Tintin book dedicated to her, The Castafiore Emerald, in which her visit to Marlinspike Hall is complicated by jewelry theft, intrigue, and other mischief. She has been arrested and used as bait to lure Tintin to San Theodoros, as well as turning up (I believe) for the first time in King Ottokar's Sceptre where her car picks up Tintin as he hitchhikes along a forest road.
She typically travels with her maid, Irma, and her accompanist, whose name I can't recall.