Um Jammer Lammy[b] 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.

The game revolves around a shy lamb named Lammy (Sara Ramirez), a left-handed guitarist and leader of a rock band named MilkCan, alongside bassist and lead singer Katy Kat and drummer Ma-san.

Although normally a nervous wreck, Lammy becomes much more confident once she has a guitar (real or imaginary) in hand.

After putting out the fire, Lammy is rewarded with some pizza but eats so much that she is mistaken as a pregnant lady by Nurse Cathy Piller.

Upon realizing she wasn't actually pregnant, Cathy asks Lammy to help put all the newborns to sleep using a baby as a guitar.

She then helps Captain Fussenpepper fly the plane while he is attacked by a ceiling panel by using her yoke as a guitar, which makes him switch personalities.

In the Japan/PAL version of the game, upon getting the guitar, Lammy slips on a banana peel and dies, ending up in a Hell-like nether world.

After being dragged into performing in a concert for idol Teriyaki Yoko (The Alien Girl), Lammy manages to earn the right to be brought back to Earth using a fax machine, but not before running into her evil twin Rammy, Yoko's original guitarist.

Um Jammer Lammy follows on from the gameplay of PaRappa the Rapper, albeit with a stronger focus on guitar playing.

Greenblat at one point suggested that the game should instead go for a more Goth theme but the rest of the team disagreed.

[2] Greenblat noted that the popularity of the internet helped ease development as he and Matsuura could more easily share ideas where as before they had to use a fax machine.

The gameplay is identical to the console version, albeit some of the game's lines are changed to make it easier to play with the guitar controller.

In 2023, after years of it being considered lost, an arcade cabinet owned by the English broadcaster Jonathan Ross was documented online and portions of the data was archived.

Most notably, in Stage 6, Lammy no longer goes to Hell after slipping on a banana peel and dying.

Reflecting the new theme of the level, Lammy wears camouflage gear instead of her regular clothing.

[5] The game was released on the PlayStation Network in Japan on February 27, 2008 and in North America on October 1, 2009.

So, to put it another way, if you didn't play Parappa to death and love every minute of it, you might as well skip out on Um Jammer Lammy".

[5] Similarly, IGN's Jay Boor commented on the gameplay, story, graphics and sound: "If you can look past all the crazy effects and wild animations, the plot isn't as funny, or as cute, as Parappa the Rapper’s.

[18] GameRevolution called it "a cool game, if for no other reason than to entertain sufficiently inebriated party guests.

[21] Next Generation said of the Japanese version, "any game that includes a stage dive deserves five stars out of hand".