- "We're all gonna die!!!"
Willie's first appearance was in the episode, "Poll Position," in which he is told that he is to become the captain of King Julien's first navy ship named Old Porceleinesides. He appears to be slightly smarter than the other lemurs, as he was imminently distraught by the fact that the ship he was to captain didn't look very seaworthy. Still, with some motivation from Maurice (who poked him with a stick to get him to move towards the boat), he gave in and accepted the honor. His worries about the boat being unseaworthy are confirmed later in the episode when the boat starts sinking, a few minutes later after King Julien flipped the switch to release the boat into the water. He is later seen in the episode being attacked by very aggressive dolphins while the boat is sinking. When he is angry with King Julien for putting him in this predicament (the sinking ship), he lets himself be bribed with the mango's King Julien was sharing to increase his popularity. After catching the mango he screams "You're the best, King J!" He is either very lucky, able to swim or rescued from the water by Clover, as he appears in the next episode in which he celebrates Franksgiving in the honor of the sky god named Frank. He once tried to smuggle in more than one wishing stone in the wishing balloon something which he is called out for by Maurice.
Willie is a very hyper and fearful lemur. He can, however, be very tough and aggressive if he's armed with dangerous weapons. Despite being slightly smarter than many of the other lemurs, he has a lot of immature moments, such as when he mischievously called out Dorothy for not wearing a diaper, and such as when he keeps screaming, "WE'RE ALL GONNA DIE!" When he screams his signature phrase, he often causes a huge panic among the citizens of the kingdom; he will however sometimes scream this when panic is already happening. Like a lot of the others, however, Willie is very fun-loving.
King Julien: King Julien is sometimes irritated at Willie's "WE'RE ALL GONNA DIE!" habit, and he sees him as tragically paranoid. He however deeply cares for Willie, like he does most of his other subjects, and he even went as far as bursting into tears when Clover mistakenly told him Willie drowned. He also has a propensity for picking on Willie. For example, when listing things which have been bad happening to them, he also lists Willie. When finding a place to store mangoes, King Julien lists Willie's hut. Willie responds with, "What the heck, man?!!"
Mort: Willie seems to like Mort, as he enthusiastically applied to be his roommate in Oh Brother Where Aren't Thou? and when he caught and affectionately held Mort in Un-King Me after Mort got thrown over the prison fence.
Ted: Though not much interaction is shown between Ted and Willie, they seem to be friends as they are often shown next to each other and sometimes spending time together.