Larry is a bodybuilder and is often seen competing or working out with other sea creatures. He is always seen in his swim trunks, even when he is not at the beach. He regularly goes to Bikini Bottom's beach, Goo Lagoon and works as a lifeguard there, as seen most notably in "SpongeGuard on Duty." Larry is one of the strongest creatures in Bikini Bottom. Larry is very popular and is idolized by many other beachgoers. In "Band Geeks," it is stated that Larry's heart once gave out from too many tanning pills, and in "Roller Cowards", he is revealed to have a bad armpit odor that is caused by adrenaline. In the event Patrick For President, Larry lost a campaign for Bikini Bottom president to Patrick, who was elected in a landslide victory with 100% of the votes.
Larry's implied parents appear in "SpongeGuard on Duty." However, they are not lobsters; they are generic "old person" character models. Larry kicks his own parents off of the beach for being too "old and unsightly," in an ironically polite manner.
He is a popular individual who has many adoring fans who crowd around him on the beach. He takes pride in being a lifeguard, knowing that he is the only thing separating the Bottomites from a watery grave. He has been seen to be furious at other characters in "Bubble Buddy" and "A Life in a Day." He has even kicked out his own parents for being old, but so politely they did not take offense to it. Despite his muscular physique, he is somewhat cowardly as shown in "A Life in a Day."
While Larry is strong and polite, he is sometimes full of himself. This is seen when he completely ignores the Flying Dutchman, instead ranting about his body. There is also a part of the song "Ripped Pants" where the lyrics are "when big Larry came 'round just to put him down." Earlier in the episode, he also acknowledges SpongeBob as something of an underling, similar to Squidward.
He can also be very extreme in sports occasionally, and when Patrick and SpongeBob land in Rippers' Reef, Larry gets very angry at SpongeBob because the three of them end up injured in the Bikini Bottom Hospital.
When Larry was young, he was assumed to have been adopted by Mable and Dennis.
Larry's first real interaction with SpongeBob is in "SpongeGuard on Duty," and he is impressed when he sees a drop of ice cream on SpongeBob's nose, thinking it is sun tan lotion.
In "Pet or Pests," when SpongeBob approaches Larry to ask about his worm pets, Larry asks, "Do I... know you?" SpongeBob replies, "Probably not." This shows that, although they have interacted before, they do not remember each other. SpongeBob's reply shows that he expects Larry not to know him at all.
In the episode "Larry's Gym," Larry attempts to build SpongeBob in his own image, and succeeds. SpongeBob acts as Larry's personal trainer after Larry loses his shape. At the end, SpongeBob’s buffoonery ends up helping Larry get back in shape.
In "SpongeBob's Big Birthday Blowout," Larry helps Sandy and the others decorate SpongeBob's house for his birthday party. After he returns, SpongeBob finds the house destroyed and everyone asleep from the party planning. Nevertheless, SpongeBob is excited that his family and friends would do so much for him. SpongeBob lists Larry and the others wonderful friends and how he's grateful to have them. When Patchy the Pirate arrives and sings the birthday song, Larry along with everyone else wakes up and properly celebrate a happy birthday to SpongeBob.
In "SpongeGuard on Duty," Patrick dislikes all lifeguards, including Larry. At the end, Larry decides to help Patrick learn how to swim after he saves him from nearly drowning in shallow water.
In "A Life in a Day," Patrick looks up to Larry as a role model, and begins trying to live like him. Eventually he loses enthusiasm for this, once he takes a stunt too far. However, SpongeBob pressures Patrick into taking part in one last dangerous stunt, during which Larry tries (and fails) to save them.
In "You Don't Know Sponge," after upsetting SpongeBob by failing to recall anything about him, Patrick meets with Larry to go shopping for a gift for SpongeBob, which initially confuses SpongeBob, as he believes Patrick has already moved on from their friendship.
Larry gets along pretty well with Sandy, since they are both into sports and both are very athletic. In "Ripped Pants," he invites Sandy and SpongeBob for weight lifting, and they both impress each other with their skills. Also, in "MuscleBob BuffPants," he and Sandy both participate in the Anchor Toss.
In "Squirrel Jelly," Sandy brutally beats Larry by hitting him hard with a volleyball and leaves him injured. He later yells at her for it once she realized that she took her competitiveness too far. This is the rare time where Larry is angry with Sandy about something.
Larry and Squidward had not been seen together until the ninth-season episode "Squid Plus One." Squidward searches for a new friend, but their chance at friendship ends after Squidward mocks him about protein shakes. Larry promptly beats Squidward to a pulp.
Larry also appears playing volleyball on a team with Squidward and Mr. Krabs against Sandy in "Squirrel Jelly."
Like Squidward, Mr. Krabs did not interact with Larry until the ninth season, but they seem to get along with each other pretty well. In "Larry's Gym," when Mr. Krabs hears that his first gym visit is free, he vows to stay there forever. Mr. Krabs teases Larry for losing his shape.
In "The Check-Up," Larry agrees to pose as Mr. Krabs in order to help the latter pass his physical. In "Larry the Floor Manager," Mr. Krabs takes a vacation and makes Larry the Lobster the temporary manager of the Krusty Krab.
In "Squirrel Jelly," Larry plays volleyball on a team with Mr. Krabs and Squidward against Sandy.
"Anybody up for some volleyball?"
"SpongeGuard on Duty"
"You know, SpongeBob, the babes in the big chair are great, but the best part is knowing that you're the only one standing between these good people and a watery grave. That's what it's all about. Their lives are in your hands now, 'cause I have a date with the tanning booth. So long."