“Harry Potter” fans will be delighted to hear that unpleasant aunt Petunia Dursley, played by Fiona Shaw, is set to join the cast of “True Blood”.

The Irish actress will appear in season four and will play Marnie, a medium and palm reader described as "mousy, timid and secretly self-loathing." 

Shaw's character appears in the fourth book of "The Southern Chronicles" on which the series is based. The original character was supposed to be younger but the profile was changed to fit Shaw.

Originally from Cork, Shaw has been awarded several accolades for both her theater and film performances.

 “True Blood” is a HBO television drama series which depicts the co-existence of vampires and humans. The fourth series starring Shaw, is expected to debut next summer.

The Irish actress is currently starring in in 'John Gabriel Borkman' at the Abbey Theater in Dublin.