I've made these costumes a few years back for my middle son who loves these characters. Also, when I made these there was no pattern or costumes sold for these as they are now.
Here is how I did each of these costumes. The hat was the most difficult because of the heavy interfacing. I used an old Sew Baby Newsboy hat pattern that went from infant to adult and I still have it but they no longer sell it. You can buy a pattern for a newsboy hat almost anywhere now.
Here is one
From Whitney Sews a free pattern
here
The interfacing for the hat brim is this kind
From Sew Mama Sew -she tells you what needle to use and other useful information -
here
You can also use felt to make the logos and either glue them on or sew them on.
I have link on the bottom to print out logos if you want to do it that way.
The shirt can be any long sleeve knit shirt that you can get at most clothing stores. You can also make your own.
Like this pajama pattern from Simplicity 1505
The overalls could be bought too or you could also make them. I made mine because it is hard to find the Nintendo colors. I made these out of flannel but you could make them from cotton, denim, corduroy, or any other heavier fabric. Depends on how heavy you want it.
Here's a pattern for overall from Burda 9464
I didn't spend to much time on shoes but you could cover a pair of shoes to match your character.
From About Home there is a tutorial on how to cover shoes
here
One last thing. The mustache! You can always pencil it on or could buy it. You could also make it.
From 5 Orange Potatoes-pattern
here for the mustache
Last gloves.
I bought the dollar store knit gloves. You could also buy ones specific for the costume but as long as they are white.
These are the cartoon ones sold at Halloween stores and cost between 7-10 dollars compared to a dollar above.
Enjoy making your costume.