he fifth season of The Fresh Prince of Bel-Air premiered on September 19, 1994 and aired its season finale on May 15, 1995. Ross Bagley was added to the show's cast, playing a now preschool-aged Nicky Banks despite the character being a newborn infant in the previous season. This is common in television series and soap operas. In the first episode to feature this change, Jazz expresses amazement while Will just stares uneasily into the camera.

Overview from themoviedb.org