Those maple trees aren't going to defend themselves! As a native Canadian, Fillion paid homage to the Internet's version of his country's superhero.
While he has been a real superhero in the past, Captain Canada's current form is as a running gag on the Internet.
After the success of Captain America's movie, places such as Tumblr and Deviantart began to wonder what the neighbor to the North's namesake hero would look like. Captain Canada spends his days defending against maple syrup shortages and writing parking tickets.
Some examples for Fillion's inspiration below!