The crazy-ass mofo from inside the windmill in The Legend of Zelda: Ocarina of Time. He is almost always seen carrying/playing his music box with a squinty grin or pissed-off look on his face. In OoT, in order to get into the well in Kakariko Village, you had to complete a time paradox involving Bob. In the future, you go to the windmill where an infuriated Bob waits. He complains of a child in green (Link) who, seven years earlier, played a song and messed up the windmill. Upon seeing your Ocarina, he remembers that day and plays the song, thus teaching Link the Song of Storms. You must then travel to the past and play the song for him, becoming the child that taught him the song and messed up the windmill.
"Yo man, don't mess with Bob the Crazy Windmill Guy. He'll cut you!"