Grumple Grommit, also known as Super Drunk, is a giant willy whistle, and one of the main antagonists of Bubble Bobble. He is responsible for kidnapping Pabblun and Pebblun and cursing Bubblen and Bobblen by transforming them into bubble dragons. While most versions of the original Bubble Bobble give the impression he did this under the orders of the Boss of Dark Shadow, the Sega Master System version (known as Final Bubble Bobble) reveals that he kidnapped Pabblun and Pebblun as brides for his two sons.
His main form of attack is to throw a ring of spinning potion bottles around himself, outwards, whilst floating around the screen and bouncing off the walls. When angry, he will do this at a much faster rate. He can only be harmed by Thunder Bubbles, of which can be obtained by drinking the Thunder Potion found on his stage.
Grumple Grommit and his nature as a character has not been established in-depth, but the tone of the messages he has written in the Secret Rooms in the original Bubble Bobble seem to show that he has an honorable disposition towards his opponents, going so far as to give Bub and Bob tips on how to defeat him, so long as they can figure out what the messages say.
Bubble Symphony shows a more vengeful side of Grumple Grommit, with him swearing revenge on Bub, Bob, Peb, and Pab for his defeat in the original Bubble Bobble. In Bubble Symphony, he is working with Hyper Drunk to trap the four dragons in the Storybook World. However, unlike in the original Bubble Bobble, he is only the first boss and he is actually not very strong. Also, it is worth mentioning that he has marionette strings attached to him, most probably because he's a puppet of his higher-ups, and serves only as another villain. He also appears patched up in this version, most likely recovering from the damage he received in the original Bubble Bobble.
Grumple Grommit is revealed to have two sons in Final Bubble Bobble, a version of the original Bubble Bobble considered by many to be the best version. His two sons are never named, but they are easily identified by their delft blue and purple robes instead of the usual green and yellow that most willy whistles have. In Final Bubble Bobble, Grumple Grommit is revealed to have kidnapped Bub and Bob's girlfriends as brides for his own two sons. Read more on that here.
In Bubble Bobble Pocket, there is a giant willy whistle that looks and acts almost exactly the same as Grumple Grommit, except he is known as Super Drunk Jr, and he is in possession of the Moon Water that Bob needs to be healed from his ailments. It is unclear how he is related to the original Grumple Grommit, or if he is at all, but some believe he may be one of the two sons. Another theory is that it is a younger Darkness Drunk. This is only speculation however, and further information has not yet been expanded upon.