Muppet Monster Adventure is a 2000 platform video game developed by Magenta Software and published by Sony Computer Entertainment for the PlayStation.

Dr. Bunsen Honeydew explains that the laboratory belonged to his late uncle and that after Robin fainted, the group of Muppets was ambushed and many of them transformed into monsters by the castle's 'evil energy'.

Informing him that the glove will only work with "the amphibian anatomy," he sends Robin on his way to collect evil energy from the village and try to save the Muppets from being monsters forever.

Robin initially fights his way through the innards and grounds of the Castle von Honeydew itself, facing its corrupt knights and guards, before defeating (and thereby rescuing) Gonzo, who has turned into the vampire "Noseferatu."

After avoiding falling prey to transmogrified hunters and evil pumpkin farmers, Robin must fight his own Uncle Kermit to save him from an eternity as "Ker-Monster" (a spoof of Frankenstein's monster).

Robin dispatches them in short order and comes to face the fearsome "Ghoul-friend of Ker-Monster" (a spoof of Bride of Frankenstein) and initiates her transformation back into Miss Piggy.

Having now gained access to the village's more mountainous regions, Robin battles through what is locally called "The Whatsamatterhorn," defeating all manner of foes including a group of violent monks.

Having saved his friends and believing his journey to be complete, Robin returns to the center of the castle only to find one final enemy awaiting him; Baron Petri von Honeydew himself (who has the appearance of Erik from The Phantom of the Opera).