Self-proclaimed "Lord of the Lemurs," Julien ruled over a great colony of lemurs in Madagascar with charisma and certainly little ability to lead. It's a goof for Julien to be a king since male ring tails are not leaders (although in the movie Maurice said he was "self-proclaimed" lord of the lemurs). Julien had parties for his people on Madagascar with much frequency, the likes of which were interrupted constantly by the Fossa, which trespassed onto the lemur villages, interrupting their parties, ripping their limbs off, stealing their women and devouring all that they could catch. The day Alex and his friends came to Madagascar, King Julien and his subjects were enjoying one of their parties when it was invaded by Fossa. When the Fossa were scared off by Alex, Julien and his people were hiding in the trees and saw this scene, thinking Alex and his friends were giants from some faraway land, with Julien coming forward and presenting himself as the king of the lemurs. When asked where the people were, Julien pointed to a skeleton of a man caught in a parachute hanging from a tree. Later that night, Julien had a meeting of the lemurs and other creatures of the jungle in the plane. Julien insisted that if they could make friends with Alex and his friends, the Fossa would be scared away for good. Maurice was skeptical about this plan but Julien insisted that, being king, his ideas were the best. When Alex and his friends were ready to go back to New York, Julien gifted them his crown; however he had already made himself a bigger, better one, with a gecko named Stevie on it. Julien proclaims that while he is in New York, Stevie will take his place as king, leaving the other lemurs speechless.
Madagascar: Escape 2 Africa
After leaving Stevie the gecko in charge, Julien, along with Maurice and Mort, accompany Alex, Marty, Gloria and Melman to New York on the plane built by the penguins. (After kicking Mort off the plane.) He is in the first class, ordering constant refreshments, and amusing himself with plane crash videos. As the plane crashes down to Africa after running out of fuel and momentum, Julien takes utter pleasure in the feeling of weightlessness caused by the high speed descent. By being in First Class, he escapes the crash with a parachute. Upon arriving in Africa, Julien at first believes they are in New York, and makes himself a new crown, declaring himself king (although nobody pays much attention). Later, when the reserve watering hole dries up, Julien suggests that they make a sacrifice to 'his good friends, the water gods' at the volcano to replenish the water. He asks for a volunteer for the sacrifice, and Melman comes forward since he believes he was going to die soon anyway. But after Melman realized he was going to live, he gave up on being a sacrifice, leaving Julien disappointed at his plan's failure. However, Mort arrives soon after, followed by a persistent shark that had been attempting to eat him. This shark then falls into the volcano, and as Julien comes out of the volcano, he sees the water coming back to the reserve (due, in fact, to a dam constructed by Nana being destroyed by Alex and Zuba), and is convinced of his plan's success.
Madagascar 3: Europe's Most Wanted
King Julien goes with the crew to Europe after crash landing their own plane (again). And appears in a lot of scenes. One of them is when he is ready to flip the switch when Maurice gives the signal and Mort holding the clock. He presses it, shutting the power down and also appears in another scene where Captain Chantel Dubois pursues them while Gloria, Melman, Marty, Alex, The penguins (Skipper, Rico, Private, Kowalski), and Maurice, Mort and King Julien go on a high speed chase in a Luxury Assult Recreational Vehicle (L.A.R.V.) when King Julien pops open the door and thinks he's famous and calls them "Paparazzi", gleefully telling them not to take his picture. He is hit with a tranquilizer dart.
The vehicle falls with King Julien while the rest are scared. The exception is Maurice, who looks hopeful. However, he lives by another plane lifting the vehicle up (to Maurice's disappointment). Later in the movie, Julien appears with Sonya (a bear he fell in love with). They go on a romantic tour around Rome, and they go to Vatican City where Julien stands in line to kiss the pope's ring. When he kisses the ring, he secretly puts it in his mouth and places it on Sonya's finger. When her tricycle is broken on the steps of the Vatican, he buys her a motorcycle instead with the pope's ring because he can't bear to see her unhappy.
They continue together, performing as an acrobatic duo on Sonya's motorbike in the circus. When the circus returns to New York and the animals are uncovered, he goes with the Zoo animals, but is shot with another dart. Not being one of the Zoo animals, he gets back to the Circus animals, who realise the Zoo animals are in danger as a result.
In the end, Julien decides to give up being a king to be with Sonya.
The Penguins of Madagascar series
Julien appears regularly, often noisily and unintentionally annoying Skipper and pretty much everyone. He is the self-proclaimed "King of the Zoo" no doubt due to his former king status on Madagascar. Only Mort and Maurice truly believe and respect him as their king, everyone else just humors him, showing up to his royal decrees.
Julien hates having anyone touch his feet, such as passing a royal decree that anyone who touches his feet would be banished from his kingdom (his habitat.) (Episode: Two Feet High and Rising.)
When the sewer rats went to the zoo and tricked the Penguins out of their home (Miracle on Ice), Julien decided to play for the Penguins in a game of Hockey to try and win their home back. They were losing until one of the rats touched his feet, after that he lost it and beat all of them on his own.
In the episode Crown Fools, Julien panics when he loses his crown and obsessively longs for it until it is revealed that he had a spare crown all along (prompting Marlene to chase him with a crowbar).
Despite his desire for everyone to listen and do what he wants, he hates and ignores Mort, his most loyal follower, who treats him like a god! most likely because Mort adores Julien's feet. Mort responds to everything Julien tells him to do as "I like..." followed by whatever Julien said.
In the episode Haunted Habitat he mentioned that he had a dream that he was "The last Mammal on Earth". Mort was just happy to be in the dream despite that he was "road kill" in it.
A recurring gag in the series, is Julien's behavior and believing in Supernatural Beings, Sky Spirits. This is ironic in that, while the Sky Spirits have shown no actual display of power and therefore could possibly not be real, he did not believe in Darla's 'backwards magic' which actually IS real.
It also shown that Julien gains a super-lemur level of strength if he gets mad visible when in Miracle on Ice, Julien spanked and humiliated the Rat King, after one of his henchmen touched Julien's feet; In Happy King Julien Day!, Maurice claims that Julien violently caned everyone who forgot his self-proclaimed holiday.
He made friends with the LEM-R unit sent to study him in Lemur See, Lemur Do. He even nick-named it Lemmy and gave him a replica crown.
All Hail King Julien
Julien takes on the role as King of the Lemurs of Madagascar, after his Uncle, "Uncle King Julien," hands him the crown, and leaves the kingdom. He has always wanted to be king.
In the episode "King Me," in spite of his selfishness, he went to save his people from the Foosa, even though he knew he could be hurt in seconds. Eventually, he is bitten on the butt by a Foosa.
When he was looking for a weapon to defeat the Foosa, he stumbled upon a Boombox. When it played a song, he couldn't help but dance to the music. He felt in his heart that music, or his moves, would be his ultimate weapon.
In the episode "Enter the Fanaloka," Karl the Fanaloka wanted to prove he was the most genius animal by defeating Julien, however Julien doesn't regard him as a foe.
King Julien's bodyguards name is Clover and even though he thinks she can be a bit paranoid, he trusts her.
Although quite lazy, his constant (virtually all the time) dancing keeps him in good physical condition, plus his natural high agility, flexibility, strength, dexterity, speed and reflexes makes him quite physically able. Ironically, he often times loses physical contests if he takes part of them (actually, if shortly, racing with Maurice and Mort, would've easily been beaten by the rats in the hockey rink if they hadn't stepped on his feet) but then sometimes shows how fit he is, such as winning Capture The Flag with his team and a limbo contest, where he was able to keep his balance throughout his body and be parallel to the ground while walking forward with his toes. It is also shown (at least in Kaboom and Kabust) that he even knows how to swim!
Although he has little (if any) combat training or experience, when motivated he is shown to arguably better than anyone. In Assault & Batteries he was able to hold his own against Skipper and even defeat him (arguably), something that no other character has been able to do, not even the other penguins. He also defeated Eggy, something no other zoo animal could do, either. Julien is also able to use twin sticks to fight, similar to the martial art "Eskrima" (). Despite that he is incredibly timid and doesn't like to fight, he only does so when angry or annoyed.
Julien is also shown to be highly durable, surviving hits and falls that should damage him greatly.
He like to whistle. He is pretty good at it now, but he would like to become a professional whistler.
Also, despite seeming very, very, very dumb making bad choices and misunderstanding simple phrases or words, it is occasionally implied that Julien is quite bright. A good example is in Go Fish, where he was able to keep up with every step in Skipper's unbelievably complex plan. Another good example is in Dr. Blowhole's Revenge, where he tricks Dr Blowhole into trusting him, while he secretly was on the right side all along (although he didn't tell the penguins that either).
In Rock a Bye Birdie he knows how the mother penguins feed their babies by chewing the fish and spits in the babies mouth. However he use watermelon to feed Skipper (who got turn into a baby) instead of fish.
King Julien is the zoo's self-appointed monarch and the ultimate party animal & is continuously full of himself, such as calling January, Julianuary & instead of saying 11, he says "Me-leven" & calling a stand-up of himself a "me-coy" instead of a decoy. This spoiled king likes to order everyone around and he would be completely intolerable if not for his insistence that everyone have fun! King Julien's towering ego more than makes up for his pint-sized body. He's quick with an insult, but even quicker with a smile, so it's hard for anyone to take this lemur too seriously. Julien very much speaks his mind; even it might be rude or mean he gives his honest opinion. He is the most eccentric character. He also fights with the penguins in some episodes. He is the penguins most powerful foe and ally.
King Julien's vocabulary and grammar levels are shown to be very -maybe extremely- low in the TV show. Example: In "Lemur See, Lemur Do", instead of saying "most disappointing" he says "disappointiest". Also, in "Popcorn Panic" he does not know that "succeed" is the opposite of "fail" and says it like "suck seed".
Sometimes he likes giving others advice (Madagascar 2, Hello, Dollface, Operation: Antartica), as he believes he has an answer for everything.
He is also shown to be very self-centered and never takes the blame for his actions. In the episode where he is jealous because Mort's dolls have become very successful, he puts them where there are skunks to spray them. When Marlene and the penguins realize that Julien is responsible, he admits it, only to say he did it in a way that it isn't his fault. ◾In Zoo Tube, when he ruins the animals' plan to show a commercial with the zoo in it, he says that it was Maurice's fault (Mort wasn't there to blame). ◾In Paternal Egg-Stinct, Julien thinks he laid an egg which was actually laid by a duck. The only mammals that lay eggs are monotremes and platypuses, and if an egg doesn't belong to a monotreme or a platypus, then it belongs to any other creature that can lay an egg, and there is no way Julien could lay an egg. ◾In the same episode, he says that Skipper, Private, Rico, and Kowalski are responsible for his irresponsibility. According to this, Julien doesn't realize that he is responsible for his actions and irresponsibility, king or not. ◾Also Julien mostly acts selfish and talking about himself a lot. And to mention that sometimes he tries to get people's attention. ◾He is an egotistical ring-tailed lemur.
Julien also seems to be very sensitive to rejection of any kind, as seen especially in All King, No Kingdom. In Otter Gone Wild, he was upset at Marlene rejecting him. In Eclipsed, he was horrified at the sky spirits' threat of never bringing the sun back, since he's so loyal to them. He expects appreciation and acceptance from everyone, but when he gets in trouble with the whole zoo, he begs for mercy even when he knows he deserves what he's given.
Because of the fact that he is extremely conceited, selfish and rather dim-witted (although he is funny), Julien is a terrible king. It seems that he will only let people talk good about him. Julien could even be narcissistic in that way. But it has been referenced twice in the series that deep down, he mainly wants his friends to stay by his side. ◾In All King, No Kingdom, after practically banishing Mort and Maurice from the lemur habitat, he soon realizes how lonely he is, and not long after starts talking to stuffed animals because he was not invited to the other two lemur's party, although almost everyone else was (It is unknown if the penguins were on the list or not). ◾Another instance is in The Lost Treasure of the Golden Squirrel, where his deepest desires are shown to actually be nothing new, and just having Maurice and Mort by his side worshiping him.
However, after the movie, Julien's dumb personality changed to serious personality because of Mort touching his feet or sometimes even worse than happen. For example in Happy King Julien Day!, Maurice has a flashback about King Julien's personality was changed to aggressive personality. In Miracle on Ice, Julien has become very enraged after the rat accidentally stepped on his feet and plucked at them. In Right Hand Man, when Maurice asking him to make Clemson a right hand man, Julien beame angry and yelled at him.