Julien Sylvester can toddle down the hall on his 18-month-old legs, can move his arms, can move his hands and he's started to laugh again, though the young boy is not quite up to what he's capable of.

It's been three days since a cougar on the hunt grabbed Julien by the head just up the beach from Kennedy Lake, in Pacific Rim National Park on Vancouver Island, sinking its teeth into the boy's skull and puncturing his brain.

But Julien got lucky, says his doctor, if one can consider luck after such an encounter.

"It's actually a fairly small area of damage and it has not caused him any definite harm," said Dr. Paul Steinbok, the pediatric neurosurgeon at B.C. Children's Hospital, who spent two-and-half hours operating on Julien.

"We would have expected that if he had a problem, he would have a problem with imbalance. But his balance seems to be good. He seems to be able to walk, he seems to be able to use his arms as normal, his motor function seems to be in good shape."

Julien's grandfather, a family friend, the boy and his four-year-old sister had packed up for the day and were heading away from the beach towards a wooded path when Julien wandered a short distance ahead.

Soundlessly, the cougar grabbed Julien, said the boy's mother, Sarah Hagar, in an interview.

"There was no sound or anything like that," said Hagar, recalling what her father told her about the attack.

"It was his friend who looked up ... and saw Julien in the cougar's mouth and yelled to my dad to get his attention."

The cat dropped Julien but lunged, unsuccessfully, for his four-year-old sister Iris before the adults managed to scare the cat off. With the animal gone, they called for help from the park's visitor centre.

"He felt ... that the animal had probably been hunting at the tree line all day, like waiting for a food opportunity all day," Hagar said of her father.

The next several hours were a blur for Hagar. She recalls she and her husband racing toward the visitors' centre, where paramedics were loading Julien into an ambulance. She remembers seeing her son screaming and writhing.

The paramedics were worried the cougar had shaken her son and damaged his spine, said Hagar.

Hagar could see a puncture wound behind the boy's head, and the blood. But she said she managed to calm her son for his flight to the children's hospital in Vancouver.

Before the surgery, Hagar said doctors gave her a list of six scenarios, from best to worst.

"It wasn't until Julien was actually out of the surgery and in the ICU that I felt like I could breathe a little sigh of relief," she said. "Like, 'OK, it's still a nightmare, but it's not quite as bad of a nightmare as it's been so far."'

Steinbok said the boy's skull was punctured and depressed in two places on the back of his head.

"We could see where the bone had been broken and pushed in and the covering of the brain had been torn in one of those areas," he said.

"There was some damage to the brain that we could see and spinal fluid was leaking out."

Doctors removed the skull fragments and used some of Julien's own tissue to close the covering of the brain.

There were also claw marks on Julien's chest that required stitches.

"He is actually quite lucky from the point of view of where the teeth of the cougar actually penetrated," said Steinbok.

"It went through the bone into the brain, but it barely missed a major vein that would have caused massive hemorrhage. It was high enough that the tooth didn't go into his spine."

Steinbok said his main concern was infection, though Julien is now on antibiotics.

But the doctor said Julien is doing well enough to return home once the antibiotic regime is finished.

Within two months, he should have all his function back. Within three, he should be completely healed, Steinbok said.

His mother takes the boy's progress in micro steps.

Her son didn't chuckle until Wednesday, didn't laugh until Thursday and he hasn't yet laughed in that "belly, kind of, toddler belly, crazy belly laugh" she's familiar with.

"I feel incredibly lucky," Hagar said.

"There were angels all along the way other than the initial attack. Everything has happened in a way to create a very promising future for Julien."