It is a double Krabby Patty with two extra slices of lettuce, cheese, and tomatoes. However, it still only has one patty.
Role in episode
Bubble Bass enters the Krusty Krab and orders a Double Triple Bossy Deluxe in a rather exaggerated way: "on a raft, four by four, animal style, extra shingles with a shimmy and a squeeze, light axle grease, make it cry, burn it, and let it swim." Squidward replies "We serve food here, sir."
After sitting down and eating the burger, Bubble Bass enjoys it, but criticizes SpongeBob for "forgetting" the pickles, as he believes them to be the best part. However, near the end of the episode it is revealed that Bubble Bass was deceiving SpongeBob the whole time, as he had just hid the pickles under his tongue.
Role in Which Krabby Patty Are You?
It is one of the patties that the player can get as a result after taking the quiz.
Bubble Bass' order for this patty, as well as Squidward's response, has become a famous internet meme.
Bubble Bass' order, if prepared properly, would be:
Double Triple: 6 patties
Bossy: All-beef patties
Deluxe: With everything
On a raft: Toast replaces buns (specifically Texas toast)
4-by-4: Four patties and four cheese slices plus the six current patties would equal ten patties
Animal style: Patties cooked in mustard and topped with secret sauce and grilled onions
Extra shingles: Extra toast
With a shimmy: Jelly on the toast
And a squeeze: Orange juice on the side
Light axle grease: Lightly buttered
Make it cry: Fry the onions
Burn it: Patties are well-done
Let it swim: Extra sauce
The Double Triple Bossy Deluxe that Bubble Bass orders is not what SpongeBob gave him. In real life, the burger would be much bigger and take much longer to prepare. If SpongeBob actually filled the order, the sandwich would have been cold and soggy by the time it left the kitchen. It would also have been physically impossible to eat due to how tall it would be.
When Bubble Bass orders his Double Triple Bossy Deluxe, he says he wants it "4-by-4" and "Animal style." Animal Style is actually a real-life burger variation with Thousand Island dressing, cheese, and grilled onions, and it was allegedly created and made famous by the California-based privately owned burger franchise In-N-Out Burger. Also, the "4-by-4" is an item on their secret menu consisting of four patties and four slices of cheese.
This was recreated in an episode of Binging with Babish, where it is shown how Bubble Bass' order would actually look like. The recipe itself was taken from a Reddit post by a user named Boothin.