Who is the new head of house

You're referring to the latest season of the popular TV show "House of the Dragon"!

As of the latest episode (Season 1, Episode 6), the new head of House Targaryen is King Aegon III Targaryen, also known as Aegon the Dragon. He is the son of King Viserys I Targaryen and Queen Alicent Hightower, and he has taken the Iron Throne after the death of his father.

However, it's worth noting that the show is based on the book "Fire & Blood" by George R.R. Martin, and the story is still unfolding. There may be more twists and turns ahead, and the fate of the Targaryen dynasty is far from certain.