When they received the invitation to Dreamnight a month ago, Adam and Jennifer Moody made plans to bring their sons, Aden, 5, and Zachary, 3.

Earlier this week, Zachary died of mitochondrial disease, the neuro-generic disorder he suffered from throughout his young life.

On Friday, the Moodys, who live in Hampton, brought Aden, his grandparents and an aunt and uncle to Zoo Atlanta for Dreamnight, a special event for terminally ill children. The concept began at the Rotterdam Zoo in the Netherlands in 1996 and is now observed by zoos and aquariums in more than 30 countries worldwide.

This is the first year for Dreamnight at Zoo Atlanta.

“We wanted this to be a fun time for Aden,” said Adam Moody of his oldest son, who is healthy. “And we’ve had kind of a hard week. It also helps just being here and seeing laughter and excitement and the joy these kids have in their eyes, like Zachary would. That strengthens us.”

While some of the 150 invited children and their guests wandered through the zoo, which was closed to the public, to look at the animals, others congregated in the Ford Pavilion, where tables were decorated with bunches of blue and yellow balloons. Mascots such at Harry the Hawk and Curious George posed for photos and family band Laughing Pizza performed fizzy songs.

Keisha Hines, director of public relations and communications at Zoo Atlanta who organized Dreamnight, said she’d received 500 RSVPs. Invitees were identified by Children’s Hospital of Atlanta as able to participate in the experience, which also included face painting, train rides with a Dream Wizard and carnival rides and games donated by Amusement Masters.

“We wanted to make it into a kids’ paradise,” Hines said.

Other Atlanta attractions, such as Georgia Aquarium, Fernbank Natural History Museum, Imagine It the Children’s Museum of Atlanta and the Michael C. Carlos Museum, donated tickets to the attendees’ “swag bag.”

Hines also found a supporter in Josh Powell, a forward for the Atlanta Hawks who spearheads a nonprofit organization called 21 Reasons to Give. Powell, a father of three children ages 1, 2, and 4, snaked through tables in the pavilion, walking up to seated guests, extending his hand and introducing himself with a quiet, “Hi, I’m Josh.”

The 6-foot-9 basketball player sparred playfully with the zoo’s panda mascot and broke into a wide smile whenever anyone asked for a photo.

Powell said the decision to get involved with Dreamnight was “a no-brainer” for him.

“As a father, I understand in some ways what other parents go through, and I can’t even imagine what it’s like for some of them. It hurts me when my own kids are sick,” he said. “I just wanted these kids [here] to enjoy a night out.”