Owen and his younger brother Ethan are climbing on the jungle gym in a park. But the story they're about to tell could be set during the Jurassic period.

"I thought it was somebody dressed in a costume," Owen recalls of the day he'll never forget. "But then I noticed it was a T-Rex!"

The eight year old says the dinosaur approached him in an Ontario airport two years ago. "I've seen Jurassic Park tonnes," he says. The boy knew he was bite-sized, so he ran.

A video shows his brother Ethan running away from the tyrannosaurus rex too. They stop fleeing from the person in the costume when they start recognizing her roar. "I didn't know who it was," Owen says. "But then I saw her face and knew it was my grandma!"

The boys' mom, Tabitha, was not surprised that her mom dressed as a dinosaur to greet the grandchildren. "She's nuts!" Tabitha says with a laugh.

"In turn that makes me nuts. And I let the kids be nuts as well."

Which is why Tabitha was supportive when Ethan and Owen started plotting a reptilian retaliation. "We came up with a plan to scare her with our raptor costumes," Owen says.

When the boys were told their grandma was coming to visit them in Victoria, they practised their roars, dressed in their Halloween velociraptor costumes, and headed to the airport arrivals lounge. "We just waited at the airport," Owen says. "To hug her scarily and then…"

And then their plan fell apart. If you look at the video of what happened, you can see the boys in the airport, dressed head-to-toe as little grey dinosaurs. Then the sliding doors open. But instead of Grandma Cheryl walking through, 'Grandmasaurus' emerges.

"She came holding a suitcase and a coffee in a T-Rex outfit! The exact same one she scared me with two years ago!" Owen says. "I did not see that coming!"

Grandma Cheryl says she may not have been scared by grandsons' greeting, be she did feel proud. "I thought it runs in the family!" Cheryl laughs.

Now Cheryl, Owen and Ethan are wearing their costumes at the park, indulging in some prehistoric playtime. "Life is short. Enjoy the kids. Enjoy life," Cheryl says. "It doesn't matter what anybody thinks!"

Perhaps Cheryl should be concerned about what her grandkids are thinking. When I ask Ethan and Owen if there is another plan to scare their grandma, they look at her off-camera before leaning close to the microphone. "I'll get her next time!" Owen whispers.

Apparently, when it comes to Jurassic joking in this family, there's no extinction in sight.