In New York City, Hector is trying to make it as a showman; he specializes in magic,
singing and piano. Unfortunately he isn't wanted anywhere, all theatre owners and audition people
know his face and already know he has nothing to offer. Feeling he needs some fresh, Hector
visits an exotic pet store to find something that he could take on stage with him. When he
hears a curious singing voice, he follows it to find a baby crocodile singing inside his cage.
Hector thinks he's perfect and instantly buys him, deciding to name him Lyle after the faded
sign on the cage. Once he takes the little guy home, Lyle proves to be shy and never talks,
but with some music played by Hector himself, Lyle opens up and joins Hector in practicing a singing
and dancing routine. The next step is renting the theatre for their new team performance,
and since Hector doesn't have any money left, he places his brownstone home as collateral. After
lots of rehearsing and covering the entire city with posters, the day of the show finally comes,
but unfortunately Lyle gets stage fright and freezes in front of the public. The show is
a total failure, and Hector must pay with the house, but he'll leave Lyle hidden in
the attic while he goes out on the road to try to get some cash back. Eighteen months later,
the Primm family moves to Hector's old house. Mr. Primm is a math teacher that has no control over
his students, and Mrs. Primm is a housewife that has written many cookbooks about eating healthy,
which she's obsessed with. Their son Josh suffers from anxiety and a bunch of phobias,
so he isn't very happy about moving to a big city full of dangers. As soon as the family arrives,
they meet the downstairs neighbor Mr. Grumps and his cat Loretta, who doesn't seem to like
her owner very much. Grump is a very strict, crotchety man that complains about everything
under the sun and wastes no time reminding the newcomers to stick to the housing rules or he'll
call a lawyer. The parents are very happy to be in a new house and Mr. Primm tries to make it more
homely by hanging up the memories of his days as a wrestling champion. Josh has a whole floor for
himself but he hates it because at night he can hear all sorts of weird noises coming from the
attic. He decides to go to investigate, and that's how he finds Lyle inside a glass box pretending to
be a doll. There's also a note from Hector asking the new tenants to take care of Lyle because he's
his most prized possession. Josh believes Lyle is fake and ignores him for now. The next morning,
Mrs. Primm walks Lyle through the busy streets of New York and the crowded subway to comfort
him through his anxiety and make sure he makes it to class. In the school corridors, Josh already
starts by making a bad first impression when he accidentally walks into a group of dancers led by
Trudy in the middle of the recording of their clip for social media. The rest of the day continues to
be miserable for Josh because he doesn't know how to socialize, so he spends breaks and lunch
alone. Later at home, Josh googles tips on how to make friends and checks out Trudy's channel
to follow her. At that moment, Loretta appears at the window to drink the milk Josh left for her,
and Josh takes the chance to bring her inside to enjoy her company. When weird noises start coming
from the attic again, Josh takes Loretta with him to investigate and this time they bump into
Lyle while he's still moving. Loretta immediately hisses at him and attacks, so when Lyle opens his
mouth in surprise, the cat accidentally jumps inside and gets swallowed. Josh yells in worry,
scaring Lyle away, and now the boy has to follow the crocodile out of the window. This means coming
down the fire escape, which is difficult for Josh because he's afraid of heights,
but he pushes through for the sake of Loretta. While Grumps hears the noises outside and starts
getting suspicious, Josh chases after Lyle through the city until he reaches a scary alley where he's
approached by a huge man that tries to rob him. Lyle can't bring himself to leave Josh in danger,
so he scares the robber away with a loud roar. After the man runs away, the roar helps Lyle
throw Loretta up, and Josh convinces him to stay by asking him to guide him back to the house. The
next morning, Mrs. Primm is finishing unpacking ingredients from a bunch of boxes and finds a bag
of chocolate-dipped cherries, which she wants to throw away because they aren't healthy. Mr. Primm
thinks this is kinda sad because she used to love those cherries, so he only pretends to throw them
away when he takes out the trash. Meanwhile Josh goes to the attic to thank Lyle for last night's
adventure by gifting him his favorite card from his hero deck. Afterward, Josh shocks his mother
by taking shortcuts through the city to go to school, feeling more confident thanks to Lyle;
he even takes the subway alone without needing his mom to come with him. Later when Mrs. Primm
returns home, she watches old videos of the family and wonders if she's starting to lose her
son. Lyle sees this because he's sneaking around the house, and when Mrs. Primm starts crying, he
decides to try to cheer her up by dropping the bag of cherries at her door without being seen. Sadly,
instead of seeing it as a cheer-me-up, Mrs. Primm throws them in the trash. Meanwhile at school,
Josh is in the library reading about crocodiles when he sees Trudy pass by, so he decides to try
to befriend her. Unfortunately he's still awkward and doesn't know what to say, prompting Trudy to
confess she thinks he's a weirdo, but she follows him back on social media anyway. In the evening,
Josh sneaks out of the house with Lyle and Loretta again because he wants more adventures. Lyle
teaches Josh to get over his fears of grossness and they go dumpster diving outside restaurants,
gathering enough to have a feast on their building's roof. Josh is hesitant since
he's supposed to only eat healthy stuff, but Lyle changes his mind by pushing some sweets into him,
impressing him with the taste. As Josh tries out food he never had before, he tells Lyle more about
his life, like the fact the current Mrs. Primm is his stepmom because his blood mom died when he was
two. Josh talks a lot but he's disappointed to see Lyle can't talk back, so to make him feel better,
Lyle begins singing and puts up a whole show that teaches Josh a few dance moves. The next morning,
Grumps notices Loretta isn't feeling well because she's been eating things she shouldn't. In the
meantime, Mrs. Primm looks for Josh and discovers he fell asleep in the attic next to a huge
freaking crocodile. Panicking, Mrs. Primm tries to take Josh away, so Lyle follows them and sings
a bit to show he's harmless. Mrs. Primm still doesn't buy it and drags Josh out of the house to
take him to school while trying to call Mr. Primm to ask for his help, prompting Josh to open up
and explain Lyle is the first friend he's made in this city and he makes him feel normal. Since Mrs.
Primm only wants her son to be happy, she accepts to keep Lyle for now. Moments later when she
returns home, Mrs. Primm finds the bag of cherries on the floor again, so she throws them back in
the trash before hearing some weird noises coming from the bathroom. When she goes inside to check,
she finds Lyle having a bath and panics as she runs back to the kitchen, saying this doesn't feel
right. To calm her down, Lyle begins singing a new song while cooking, the lyrics telling Mrs. Primm
that life needs more sugar and surprises instead of the same monotony every morning. Tasting sugar
again reminds Mrs. Primm of her love for the craft, and soon she's baking and singing with
Lyle, having fun like she hadn't had in a while. She also starts painting again, and when she
goes to bed, she's so happy with her life again that Mr. Primm begins getting suspicious. When
Josh comes back from school, he finds his mother singing with Lyle and loves it, thus they begin
bringing her to their night dumpster adventures. All the noise they make is making Grumps more and
more paranoid, causing him to install security cameras outside all his windows. One morning, Mr.
Primm notices they're having pizza for breakfast and finally breaks. He tells his wife he's noticed
she's changed and wonders if she's found a new love, so Mrs. Primm has no choice but to tell
him about Lyle to stop him from getting the wrong idea. As soon as he sees the crocodile, Mr. Primm
panics and tries to run away, but when he opens the door he's shocked to see Hector outside. Lyle
is offended after being abandoned and doesn't want to see Hector at first, but Hector quickly
wins him over by remaining him of the tunes they used to share. Mrs. Primm calls their landlord and
learns that as part of the deal that cost him his home, Hector can stay in the house fifteen days
out of the year, so he'll be sleeping in the attic with Lyle. This means they stay up late singing,
which makes it hard for Mr. Primm and Grumps to sleep. The next day is supposed to be family day,
but Mr. Primm is too weirded out by these changes in his life and decides to go for a run alone.
Hector joins Mrs. Primm and Josh and tells them they can bring Lyle if the wears a Gators team
t-shirt, because nobody on the streets will want to believe there's an actual crocodile hanging
out in New York. The four of them end up having lots of fun together visiting all the emblematic
spots in the city, and by the time Mr. Primm returns home, he finds everyone playing games
together. Still weirded out by this, he decides to ignore them for now, so Lyle goes after him
to try to change his mind. He brings Mr. Primm his old wrestling uniform and asks him to fight,
then pretends to lose to make Mr. Primm happy. Now that he's feeling confident in himself again,
Mr. Primm becomes capable of controlling his troublesome students and is happy to have Lyle
and Hector around. One afternoon, Hector shows his appreciation of the family with a wonderful
magic show, he also manages to drag a hesitant Lyle with him to perform at least one song. Lyle
is comfortable because he likes the Primms, but Hector doesn't understand this and thinks Lyle
is ready to try a public stage again. When Hector is in the process of taking Lyle to another talent
contest, and when Josh sees them he protests against the idea, explaining what Lyle needs are
a family and a home. Hector disagrees and informs Josh that Lyle's destiny is being a showman,
then takes the crocodile away in his bike. Hours later, Hector returns bad news: Lyle froze on the
stage again. Josh rushes to hug his friend to comfort him and remind him he's awesome the way
he is while Hector sneaks out of the window to go looking for some way to make money to pay his
debt. The next day, Grumps drags the Primms into a HOA meeting to accuse them of hiding something and
trying to get the other neighbors to vote for them to leave the building. The Primms don't know how
to defend all the noise Lyle has been making but luckily they're saved by Hector, who interrupts
the meeting to point out Grumps installed his security cameras without official permission,
meaning he's technically spying on everyone. Furious over being caught being a hypocrite,
Grumps kicks everyone out while still promising revenge. The Primms thank Hector for his help, but
he disappears pretty quickly, and they soon learn why: Wildlife Control is here to catch Lyle after
Hector sold them the information. Josh desperately asks Lyle to sing to prove he isn't a wild beast,
but Lyle still can't sing in front of strangers and is taken away to the zoo. All this is seen
by Grumps, who finally has proof to sue them properly. The following day, the Primms go to
visit Lyle at the zoo. Josh wants to rescue Lyle, but his parents point out this may be for the
best since Lyle will be with other crocodiles and have experts looking over him. This upsets Josh,
who begins babbling about the fact Lyle made him a braver person, triggering a panic attack that
makes him pass out. That night, Lyle spends it in a corner by himself singing, because he can't
connect with the other crocodiles. Meanwhile Hector is leaving the city with his cash,
and the lack of Lyle in everyone's lives becomes very obvious: Mr. Primm puts away his wrestling
uniform, Mrs. Primm loses her inspiration to paint, Loretta won't eat anything, and Josh falls
asleep in tears on Lyle's bed. At school the next day, Trudy approaches Josh to tell him her dance
group will be on a talent show and notices he's in a blue mood. To help him keep hope, she shares the
story of her rattlesnake, who went missing for six weeks. Trudy thought her dear pet had died until
the neighbors found him, so miracles do happen. In the evening, when Josh finds Hector waiting
outside the house. He explains he had acted out of fear and need, but he regrets his actions, so they
need to put their differences aside to save Lyle. This isn't enough for Josh to believe Hector's
changed his ways and ignores him. Not willing to give up, Hector shows up at the zoo alone,
where he handcuffs his own hands to the bars. When the security guard comes to see what all
the noise is about, Hector tricks him with magic and handcuffs the guard's hands instead, getting
to steal the zoo keys in the process. Next, Hector sneaks inside the crocodile pit, but Lyle ignores
him while the other crocodiles begin getting dangerously closer. At that moment, Josh shows up,
but he refuses to help Hector because first he must make things right. Hector understands and
finally apologizes to Lyle, admitting he's used him but those days are behind - from now on,
he'll allow Lyle to live with his true family, the Primms. This finally makes Lyle react,
and he accepts to escape with them. It's already morning by the time the trio leaves the building,
and there are a bunch of cops waiting for them outside. Hector explains he has his bike parked
nearby, but Josh thinks Lyle can't constantly live on the run, they have to find a way to show the
world who he really is. Suddenly, a bus drives by promoting the talent show Trudy will be attending,
and Josh knows that's their only chance. While Hector distracts the cops with some magic, Lyle
and Josh get on the bike, and when Josh expresses fear of driving, Lyle convinces him to be brave
by showing him he still has the hero card he had gifted him. Josh drives the bike quite clumsily
but still manages to make it to Time Square while calling Trudy to ask her to open the backstage
door for them. When she sees Lyle she gets quite scared, but Josh quickly explains and Trudy
accepts to give them her spot in the contest. Lyle and Josh manage to force their way into the stage,
and everyone panics when they see a real crocodile. This reaction makes Lyle freeze again,
especially since the cops and animal control are arriving too, so to make him feel better,
Josh starts singing on his own even if he's terrified and an awful singer. Seeing such
a brave act from a child helps Lyle overcome his own fears and he soon begins singing too,
getting Trudy's group to join him as his backup dancers. The audience and the jury love him,
and the cops finally back away. A month later, the Primms find themselves in court because Grumps is
suing them for keeping an exotic animal as a pet, which is illegal. The judge thinks Grumps
is right, but before he can announce his official decision, Hector shows up with big news. Thanks to
Loretta's help, he's recovered the original deeds to his house that Grumps had stolen from him, and
these papers reveal his house used to belong to his grandmother who founded the New York City Zoo,
thus the City of New York assigned a special waiver to house any exotic creature as a pet
in the building. The judge immediately rules in favor of the Primms, and as the family celebrates,
Loretta finally abandons Grumps and jumps over to their side to be their pet too. A few dates later,
the Primms leave on a vacation, bringing Lyle and Loretta with them. Hector is a bit disappointed
because he had already booked performances for Lyle, but he soon solves this issue when Trudy
approaches him with the perfect replacement: it turns out her rattlesnake is an amazing beatboxer.