Why did they call him Yogi?
When he started playing in the American Legion baseball leagues, they had no dugouts or benches for the players. Berra used to sit indian style in the dirt with his arms and legs crossed. One of his teammates, Bobby Hofman, said he looked like a yogi (a hindu holy man), and the nickname stood.
His name was not to be confused with cartoon character, Yogi Bear, which was not named after Berra. According to the creators of the character, Hanna-Barbera Productions, the two were not connected.