According to Hanping Chinese Dictionary that huge character on Wukong's cap, 佛, means "buddhism"*. It feels a bit like L for Learner, or those trainee signs companies provide, to make sure people know those unruly newcomers actually belong. Yep, it took me 39 episodes to look it up, despite wondering over it from the start. Speed is _not_ my middle name.
(*as well as "seemingly" and "(female) head ornament")
