Toronto's Fred Kelly created Jim Stearne in, I believe, 1946, and the character first appeared in Triumph #31. Stearne then appeared as Mr. Monster in Super Duper #3 the following year.
And...That was about it until Michael T. Gilbert created his own version of the character. Gilbert's wrote the tales of Jim Stearne's son, Strongfort. He fleshed out Jim's background a fair bit as well, though he made him an American that traveled to Canada (as opposed to being Canadian born, raised and educated) in the process.
Still, at his root, Mr. Monster is among the first Canadian superheroes and getting an action figure of him would be a real treat. FMF's next Kickstarter campaign is said to be launching "later this summer" and I very much plan to participate.