Firstly, Finn Wolfhard doesn't play Aegon II – in Episode 6, he's portrayed by Ty Tennant, the son of David Tennant.
Doctor Who's ties with the GOT universe to continue: David Tennant & Georgia Tennant's son, Ty Tennant, is a Targaryen on House of the Dragon.
David Tennant's son Ty Tennant is stepping into the role of Aegon II, a major player in the events to come. Nick Romano.
Ty is well-known to fans of Doctor Who (2005). His maternal grandfather, Peter Davison, and adoptive father, David Tennant, played the Fifth and 10th Doctors,
Ty Tennant (born 27 March 2002), also known as Ty Peter Moffett, is an English actor. He is known for his roles as Edwin Paine in Doom Patrol
Ty Tennant will play an older Aegon Targaryen, the son of King Viserys and Alicent Hightower.