Larry is a bodybuilder and is often seen competing or working out with other sea creatures. He is always seen in 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, viewers and fans were asked to choose between Patrick and Larry the Lobster for Bikini Bottom's future president. 100% of the votes went to Patrick. In the end, it was not an actual contest, but an advertisement for a week of Patrick-themed episodes. Nickelodeon had to think of an unfamiliar character for Patrick's "competition," so they chose Larry. The New York Times reported: "it's safe to assume that the starfish's nominal opponent, a minor character named Larry the Lobster, doesn't stand a chance."
Larry's implied parents (Mable and Dennis) appear in "SpongeGuard on Duty". However, they are not lobsters; they are generic "old people" 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 is generally kind, polite and supportive. However he has been seen to be furious at other characters in "Bubble Buddy", "A Life in a Day, and "Squid Plus One" when they put him in danger or insult him. 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 and bravery, he knows when to draw the line, 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.
Larry's first real interaction with SpongeBob is in "SpongeGuard on Duty" and he is pretty impressed when he sees the drop of ice cream on his nose, thinking it is sun tan lotion, or as it is referred to as, "white stuff." Larry seems to interact well with SpongeBob, talking to him when he's around and creating small talk with him quite often, as he asks him to help him spread sun tan lotion on himself in "The Abrasive Side," and compliments him in "Pets or Pests."
In "Pet or Pests" when SpongeBob asks Larry 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 really remember each other well.
In the episode "Larry's Gym," Larry attempts to build SpongeBob in his own image, and succeeds. Later, all of the paperwork causes Larry to neglect his body, and his muscles deteriorate. SpongeBob becomes Larry's personal trainer and helps him get his old body back. After working out, the two share a hug.
Patrick's opinions about Larry have changed drastically throughout the show, going from disliking him to idolizing him, and eventually seemingly being acquaintances with him. In "SpongeGuard on Duty," it is implied that Patrick does not like lifeguards much, as he criticizes them for being overrated, stating that all they do is blow on their whistles, rub white stuff on their noses, and show off their bodies. 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, but 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 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.
Like Squidward, Larry's first encounter with Mr. Krabs is in the ninth season, in the episode "Larry's Gym" When Mr. Krabs hears that the first visit at his new gym is free, he vows to stay there forever. After Larry starts to lose shape, Mr. Krabs starts to tease him. Larry falls into a deep depression until the end of the episode, when SpongeBob helps him get back into shape. Mr. Krabs is cooked alive after spending too much time in the tanning salon short after.
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.
Larry has gotten along 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.
However, in "Squirrel Jelly," Sandy brutally beats Larry by hitting him hard with a volleyball. Later in the episode, he scolds her for it.
"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." — "SpongeGuard on Duty"
"How would you like to take the second shift?" — "SpongeGuard on Duty"
"I think you're ready." — "SpongeGuard on Duty"
"SpongeBob, are you okay?" — "SpongeGuard on Duty"
"You're not a lifeguard, are you?" — "SpongeGuard on Duty"
"I'll tell you how: by living each day as if it were their last!" — "A Life in a Day"
"Living like Larry!" — "A Life in a Day"
"Look, guys, my advice wasn't meant to be taken literally! I meant to live life to the fullest, not to maim yourselves! Look!" — "A Life in a Day"