Who is Dum in the tinkle comics?

There isn't a character named "Dum" in the Tinkle comics. It's possible you're thinking of another character or have misremembered the name.

Could you provide more details about the character you're thinking of?

For example:

* What did they look like?

* What were they known for?

* What were their relationships with other characters?

* In which Tinkle stories did they appear?

With more information, I might be able to help you identify the character you're looking for.