Leelu was a narwhal that Fry befriended during the years he spent in the past on the run from Bender, who was out to kill him. Leelu had an obvious connection to Leela in Philip I's mind. Beside the fact that she was purple, Philip I tells Leelu upon their first meeting, "Hiya girl, my name's Fry. I think you're a cutie because I like things that have only one thing instead of two things."
Philip I is the only person who had been able to get Leelu to eat, curing her of her sickness. Throughout the years, their relationship blossomed and they became best of friends. Philip I was heartbroken when he learned that Leelu was being released into the wild to make room for the Loch Ness monster: in actuality a log with a Halloween mask stapled on to one end.
Philip I searches for Leelu
Philip I took Panucci, his old boss, to the docks, where Panucci introduced him to his cousin Leroy, the captain of a ship. Leroy agreed to take Philip I out to sea to search for Leelu. Philip I 's plan was to "capture a narwhal and bring it back to his room".
After two years of searching, Philip I finally found Leelu, who promptly recognized her best friend and jumped up to greet him in a happy reunion. However, when he tried to take her home, she was upset: it seemed that she had fallen in love with a male narwhal that was following the ship. Philip I finally learned his lesson when he saw Leelu so upset. He realized that she needed what would make her happy, not what would make him happy. Leelu appeared to have a thankful look on her face when Philip I let her go to the male; however, she became sad upon watching Philip I say goodbye to her again. This is another reference to Lars and Leela's relationship: Philip I needed to let Leela be happy with Lars, as much as he disliked it.
- Even though she's female, she has a horn, which in reality, only the male narwhals have. Although, both sexes are born with those tusks, only the males left tusk grows. Ironically her voice actor (Maurice Lamarche) is a man.
- Her name is pronounced "Leeloo" like the sci fi character from The Fifth Element