Robin Williams would always give money to those in need

Zak, 41, - whose mother is Robin's first wife Valerie Velardi - told People: "When I was a little kid and we'd be walking in San Francisco where I grew up, he would stop, talk to someone on the street - a homeless person - say, 'Hey boss, what can I do for you?'

"And we'd see him get meals, food, money.

"He cared deeply about people in need, and I think for me, he opened my eyes to really what kindness was all about."

Zak and his siblings Zelda, 35, and Cody, 33, - both of whom are from Robin's second marriage to Marsha Garces - have now made it their mission to continue their father's philanthropic legacy by continuing the work he did with various charities over the course of his life.

Zak added: "It was deeply important to him to help improve the human condition, and that extends beyond helping people laugh and learn about themselves.

"It also related to how he could actually support organizations materially by helping raise funds and awareness for organizations like the Challenged Athletes Foundation, the [Christopher Dana Reeve] Foundation and St. Jude's, among many others.

"We see it as a natural extension of what he would want, which is helping bring healing and helping develop resilience for folks, especially young people. He loved kids.

"And as a family, we feel it's a natural way to honor his legacy."

At the time of his death, the 'Jumanji' star had been married to Susan Schneider for three years and his ashes were scattered in San Francisco Bay.