Thousands of people took to the streets of San Francisco on Sunday for the annual Bay to Breakers race. A San Francisco tradition since 1912, Bay to Breakers is famous for the outlandish costumers — or lack of — worn by race participants.

What do inflatable rubber ducks, tipsy popes and a space-bound Katy Perry all have in common? They were among the flashiest costumes at Sunday's Bay to Breakers, a 12K and 15K race stretching all the way from downtown San Francisco to where the ocean meets the Great Highway.

Thousands of people hit the streets of San Francisco for the annual Bay to Breakers race on Sunday. The first wave of runners left at 8 a.m., and the last wave will left at 8:45 a.m. from Main and Howard streets.