Nick Katsoris has found that it never hurts to ask—especially when the subject is a fluffy Greek lamb who raises money for children’s charities.

Asking is how Katsoris has convinced actors, including Jennifer Aniston, Olympia Dukakis and Morgan Freeman, to record the audio versions of his children’s books about Loukoumi the lamb. And asking is how Katsoris improbably found himself sitting at NASA’s Jet Propulsion Laboratory next to an aspiring Mars rover engineer, watching the landing of the Mars Phoenix.

Katsoris ended up at NASA after organizing a contest in conjunction with his series of six books about Loukoumi. The Growing Up With Loukoumi Dream Day contest invites children to draw a picture of their dream day; Katsoris makes the winner’s dream come true. When the winner—a young girl who said her dream was to work with the Mars rovers—was chosen, Katsoris had no idea how he would deliver the prize. So he just called NASA and asked for help. The person he spoke to had a solution: “She can sit inside mission control as we land Phoenix on Mars.” Katsoris made the necessary arrangements and was sitting next to the contest winner, watching the scientists at work, when she told him, “Because of this, there’s no doubt I want to be a Mars rover engineer.”

Experiences like that one (subsequent Dream Day winners have played with the New York Red Bulls and cooked with Rachael Ray) remind Katsoris why he began publishing the Loukoumi books in 2005. Loukoumi takes her name from the Greek word for “sweet,” which is also the name of a confection. Katsoris, a second-generation Greek-American who is 47 years old, had the idea for the series 14 years ago. He asked his wife to pass a dish of loukoumi and then thought, “Wouldn’t that make a cute name for a children’s book character?”

Over the course of six books, Loukoumi has traveled the world, followed her dreams, learned to cook, and faced up to the schoolyard bully. Each book—Katsoris has two more in the works—is focused on a child-appropriate lesson, and Katsoris, who lives in New York, encourages readers to participate in Loukoumi's philanthropy. Beginning with the 2009 release of Loukoumi's Good Deed, Katsoris has organized an annual Make a Difference with Loukoumi Day, in which children commit to doing “whatever good deed it is they want in their hearts,” from promising not to argue with siblings to making charitable donations. “After five years, we're up to 20,000 kids taking part,” Katsoris says.

Katsoris, a corporate lawyer by day, says “lack of sleep” is what allows him to manage a professional career, two young children and a successful series of books. He works closely with the illustrator on book design and relies on feedback from several first readers—including his children, who he says are “the perfect age” for offering insight into Loukoumi’s appeal. Baker & Taylor is the books’ primary distributor, although Katsoris, with the help of a sales agent, has worked directly with Follett and Barnes & Noble to place the books in chain stores. “We’ve had national distribution for the series, which has been great,” he says.

Loukoumi also does her part for charity. Katsoris says that over the course of the series, he has donated more than 10,000 copies of his books to literacy organizations, and the profits from the books' sales are also donated. “We just passed the $100,000 mark of donations we've been able to make to children's charities,” he says. In February, the Loukoumi series was chosen as one of 10 winners of USA Weekend's National Make a Difference Day grants. Among the organizations Katsoris focuses on is St. Jude's Children's Research Hospital, which he has worked with since 2009. In addition to monetary donations, he makes regular visits to the hospital and loves reading Loukoumi books to the patients.

Katsoris was introduced to St. Jude's by actress Jennifer Aniston, a longtime supporter of the hospital, after she narrated several of the Loukoumi books. He knew Aniston's father, John Aniston, through the Hellenic Times Scholarship Fund and asked John, also an actor, if he would be interested in narrating Loukoumi's Good Deeds with his daughter. “I almost drove off the road” when Jennifer called to tell him she was happy to participate, Katsoris says.

Some of Katsoris’ celebrity narrators have come from connections forged through the scholarship foundation, but others have taken part simply because Katsoris asked them to, reaching out through their agents or through public contact information. For the most recent book, Loukoumi and the Schoolyard Bully, he says, “I realized I needed somebody for the bully, and there's no one with a better voice than Morgan Freeman.” Freeman, it turned out, was delighted to participate.

In addition to providing a character's voice, Freeman has also contributed a recipe to the upcoming Loukoumi's Holiday Cookbook. This is the second recipe collection, following the success of Loukoumi's Celebrity Cookbook (2011). Katsoris' partner in that cookbook was Iron Chef Cat Cora, who appeared as a character in the book, teaching Loukoumi to cook. Nicole Kidman, Faith Hill, Beyoncé and Oprah Winfrey are among the celebrities who shared favorite childhood recipes. Katsoris still sounds amazed when he describes the email Winfrey sent in response to his query: “Not only did she say yes, but the recipe was attached.”

Katsoris says he is able to bring so much energy to the Loukoumi series because writing the books and coordinating the charitable donations does not feel like work. “I feel like what I'm doing with these books is what I was meant to be,” he says. “As long as people keep reading them, I'll continue to write them for the rest of my life.”

Sarah Rettger is a writer and bookseller in Massachusetts.