The Wikipedia article acts as though Hector had appeared in other things before Hector: Badge of Carnage, yet I can't seem to find anything else. Did Straadlooper create him from something else?
Not that I'm aware of. I don't see in the Wikipedia article where it implies he was in anything else.
There were a couple Hector: Fat Arse of the Law shorts released on Straandlooper's The Hector Files Youtube channel a few months before the first episode of the game came out on iPhone.
There was apparently originally supposed to be a series of full length animated movies based on the shorts, but those never saw the light of day. Instead of those films, it seems we got Hector: Badge of Carnage.