What is in the core of Sirius black's wand?

In the core of Sirius Black's wand is a single hair from the tail of a particularly aggressive and powerful dragon, known as the Hungarian Horntail. This core material is known for producing wands that are highly effective for defensive and combative magic, as well as for their resilience and durability. The choice of dragon heartstring as a wand core signifies strength, courage, and a fierce nature in the wizard who wields it.