The Oklahoma City Zoo throws 1st birthday bash for 5 lion cubs: VIDEO EXTRA

The Oklahoma City Zoo marked a major milestone Tuesday as its five lion cubs celebrated their first birthday with treats, toys and playful antics.

The cubs, born on May 20 of 2024, were treated to a special enrichment event.

MORE COVERAGE: OKC Zoo celebrates five lion cubs' first birthday

"Today we're doing a really great enrichment event, giving them lots of fun treats and things to play with to celebrate their first birthday," said Jennifer D’Agostino, Chief Animal Programs Officer at the Oklahoma City Zoo.

"Today we're doing a really great enrichment event, giving them lots of fun treats and things to play with to celebrate their first birthday," said Jennifer D’Agostino, Chief Animal Programs Officer at the Oklahoma City Zoo.

However, the celebration didn’t go exactly as planned.

"Animals don't always follow our plans, no matter how hard we try, and so dad threw a little bit of a wrench in the works today," D’Agostino said. "He refused to come inside, so the animal caretakers were really not able to set up the enrichment in the way that they wanted to, but it's okay. We make do with that. And we ended up going to plan B and taking that enrichment and throwing it off the roof so that the animals could still have a fun time."

Despite the hiccup, the cubs enjoyed their birthday celebration.

"They absolutely love to play. Now, I think their number one play toy that they love the most is each other. They constantly are wrestling and fighting each other and learning those skills that they're going to need to be as adult lions," D’Agostino said.

The birthday enrichment included cardboard boxes, cantaloupes and their all-time favorite toy — a jolly ball.

"Today we gave them cantaloupes, even though that's not something they would normally eat in their diet. Because they are carnivores, they love to chew on it, break it apart, run around with it, play with it like a ball," she said.

D’Agostino added that the cubs are growing rapidly and are in good health.

"They grow incredibly fast. They're eating a ton of food. They're very active. They have great muscle mass. They're doing really well," she said.

Each cub weighs just under 200 pounds and is expected to reach 400 pounds at full maturity — about the same size as their father, Hubert.

In addition to their physical development, the cubs have made significant behavioral strides through training.

"They've hit all of their milestones. They're in a really good behavioral training program as well. So all of those lion cubs have voluntarily given blood from their tail vein without having to be under anesthesia. They're all except injections. So we can give them their vaccines without again having to restrain them or do any anesthesia. So they're they're really, really smart," D’Agostino said.