Although apparently one of the leading opera singers of her generation, the only thing that Castafiore is ever heard to sing is the opening line of the Jewel Song from Faust, always at ear-splitting volume: "Ah my beauty past compare, these jewels bright I wear!" Unsurprisingly, opera was one of Hergé's pet hates. She is said to have been modeled on real-life opera singer Maria Callas.
She has a crush on Haddock, for whom she has a strong mothering instinct. She always pronounces his name incorrectly ("Capitaine Karbock"), and whenever she showers him with tokens of affection the results are disastrous. She later gets involved in rumours surrounding an affair with Haddock - much to the Captain's chagrin.
Tintin albums featuring Castafiore