Um Jammer Lammy is a 1999 rhythm video game developed by NanaOn-Sha and published by Sony Computer Entertainment for the PlayStation. It is a spin-off and follow up to 1996's PaRappa the Rapper, once again featuring the collaboration of music producer and game designer Masaya Matsuura and artist Rodney Alan Greenblat. An arcade version co-developed by Namco, titled Um Jammer Lammy NOW!, was released in Japanese arcades in December 1999. The game received generally positive reviews from critics.