Mr. Mugs is a sheep dog who was featured in these readers I used when learning how to read. Mr. Mugs taught me to read, and since he's no longer part of the Canadian school curriculum, I preserved him for all of eternity.
Ranking #2 in Google for Mr. Mugs results in lots of interesting emails like the one below from Patrick.
I am not from Canada (from the states) and am assuming that Mr. Mugs was a Canada specific series of books. I found your site because I googled " mr. Mugs" as I have a button with his name on it that my grandparents had in the bottom of an auction box they purchased maybe 15 years ago.. it has been stuck in a bulletin board in my classroom (I teach) for years now, and I have been trying to find out what on earth Mr Mugs is!
Here's the button Patrick found. If you remember Mr. Mugs, you'll get a kick out of this.