Harry Potter: Hogwarts Tournament of Houses Finale Airs This Weekend After a nail-biting wildcard round that saw team Slytherin narrowly defeat team Gryffindor, Harry Potter: Hogwarts Tournament of Houses continues Sunday, Dec. 19 at 8:00 p.m. on TBS and Cartoon Network with the grand finale. The final installment, once again hosted by Helen Mirren, promises an exciting battle between the loyal Hufflepuffs, …