Yosemite Sam could be one for the really rottens. Not sure if a generic bulldog could since many cartoons had a bulldog char who was a bully or bad guy. Though some had a bulldog char as a good guy also. Maybe some other recognizable chars like Tom the cat, and from some other recognizable chars from various other series like one from the 80's turtles, a road rovers villian, and others maybe.
Also with non hb chars woudl they be in their own team or would they be in a team of their choosing or would it be based on the spirit of the hb teams, like chars from before 1970 would be on yogi's team and those from 1970 and after on scooby's team, apart from the dogs team?