The PaRappa the Rapper clip in question is test footage for the opening animation of the game, featuring placeholder voice acting and characters in place of the final product.
New early test footage uploaded by artist Rodney Alan Greenblat showed that prior to development on the game beginning, PaRappa seemed to be very different sort of Rapper.
PaRappa the Rapper originally debuted on the PlayStation, but was remastered for the PS4 in 2017.
Though all the characters in the test footage look different from their final iterations, PaRappa himself is replaced entirely with generic blue character.