Most West Coast and Fremantle fans would rather walk over hot coals than 'barrack' for the other WA-based team.

But one man switches his allegiance from the Eagles to the Dockers every week, although he manages to avoids a barrage of abuse for doing so because nobody can see his face.

The reason for the swinging loyalty is because Simon Lumbus is the mascot for both clubs.

At West Coast home games the 43-year-old father of three is Rick "the Rock", but when the Dockers play at Domain Stadium he is Johnny "the Doc" Docker.