TORONTO -- Sunday's Google Doodle pays tribute to famed Canadian athlete and cancer activist Terry Fox on the anniversary of the first run event organized across Canada in his honour.

The Doodle, illustrated by Toronto-based artist Lynn Scurfield, replaces the usual Google logo with an image of Terry running in a valley near a lake. The sun shines above him and the clouds in the background spell "Google."

The illustration pays homage to Terry’s original "Marathon of Hope" which he started on April 12, 1980, three years after he was diagnosed with bone cancer and had his right leg amputated.

Beginning in St John's, N.L., Fox ran almost 42 kilometres every day for more than four months in his ambitious cross-country mission to raise money for cancer research. But by kilometre 5,373, the cancer he’d been fighting spread to his lungs, and he was forced to stop running.

Sept. 1, 1980 marked the last day of the Marathon of Hope. Terry died in hospital the following summer at the age of 22.

"Thank you, Terry, for every step you took towards the cancer-free world you bravely envisioned," Google said in a statement about the Doodle.

In his honour, the first Terry Fox Run event was held on Sept. 13, 1981 at 760 sites across Canada. Now, the Terry Fox Run has become an annual event held worldwide.

His older brother, Fred Fox, said that Terry would be "so proud" of the legacy he left behind.

"Here we are 40 years later and new generations of children are learning about Terry, and 9,000 schools in this country host Terry Fox events," Fred told CTV News Channel on Sunday from Maple Ridge, B.C.

Fred added that he heard from teachers at the beginning of the year already looking at ways to start fundraising and get their students involved.

"Now that school is getting going, they're all doing things a little bit differently this year in school, but they're still going to be learning about Terry, he's part of the curriculum," he said.

On Sept. 20, a virtual Terry Fox Run will be held across Canada. Participants are invited to collect pledges and then embark on their own non-competitive run or walk in their community. Nearly 14,000 runners have already raised over $2 million for this year’s event.

Fred said on July 11, 1980, Terry made a speech in Toronto and told the crowd that even if he couldn’t finish the "Marathon of Hope," others had to continue it.

"That's what Canadians have done for 40 years, keeping cancer research prominent and that's what Terry wanted... It's really impacted the lives of so many people," Fred said.

Terry’s original goal was to raise $1 for every Canadian -- $24.17 million -- which was achieved just four months before his death from fundraising events held on his behalf.

Since then, more than $800 million has been raised to support cancer research in his name.