As a fan of the FC St. Pauli (Hamburg, Germany) I recently recognized, that this football club must be His favorite one.
Just follow the link and you will see, what I mean.
Since many years now, the skull is one of the famous symbols of the fanscene. The pirate flag waves every time, the team of the FC St. Pauli plays - that is not by chance!!
FC St. Pauli Skull