It is a double Krabby Patty with two extra slices of lettuce, cheese, and tomato.
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 tells him, "We serve food here," but SpongeBob appears to have already made his order anyway. SpongeBob then realizes who he is serving the patty to and Bubble Bass informs him that he heard he makes "a mean Krabby Patty."
After sitting down and eating the Double Triple Bossy Deluxe, Bubble Bass deems it to be pretty good, 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 an answer after taking the quiz.
Bubble Bass' order for this patty has become a famous internet meme.
Bubble Bass' order would be:
Double Triple: 6 patties
Bossy: All--beef patties
Deluxe: With everything
On a raft: Toast replaces buns
4-by-4: Four patties and four cheese slices × 6 current patties = 24 patties and slices of cheese
Animal style: Patties cooked in mustard
Extra shingles: Extra toast
With a shimmy: Jelly on the toast
And a squeeze: Orange juice on the side
Light axle grease: With butter
Make it cry: Extra onions
Burn it: Patties are well-done
Let it swim: Extra sauce
Such a patty would be a towering 28 inches (71.12 cm) and weigh a whopping 9 pounds 5.3 ounces (4.2 kg)!