"Humdinger" is defined as a person or thing of remarkable or superior excellence. This is indicative of the Foggy Bottom mayor's haughty, egotistical attitude and great desire to be the best in anything in which he participates.
Mayor Humdinger is known to be very angry when he loses. He also has a strong rivalry with Mayor Goodway.
It is proven that he doesn't care if his actions hurt somebody as long as he wins. (e.g. cheating at basketball and hurting pups.)
He also has no problem when it comes to stealing something if he wants it.
Mayor Humdinger's manner of dress and behavior resembles the classic archetypical mustached villains (like Snidely Whiplash or Dick Dastardly) and even shares several many classic mannerisms such as stroking his mustache, villainous laughter, and hand-rubbing. His habit of cheating in various competitions in Season 2, is similar to Dick Dastardly from Hanna-Barbera's Wacky Races. In Pup-Fu!, he depicted even more like a typical villain to the point he has a secret lair for himself and the Kitten Catastrophe Crew, which has a monitor which he uses to spy on his enemies (a villainous trope).
In Season 1, while antagonistic towards Mayor Goodway, Mayor Humdinger for the most part played fairly in all the competitions he competed in. However in Season 2, he began cheating and/or playing unfairly in order to win. The likely reason for this change is that in Season 1, he had generally been undefeated in the various competitions and was quite confident in his ability to defeat his competition and win. However due to being defeated by Mayor Goodway and Mr. Porter in at least two different competitions due to help from the PAW Patrol, he likely lost his confidence that he could successfully win competitions fairly and began cheating and playing unfairly in order to ensure his (and/or his town's) victory. He even creates the Kitten Catastrophe Crew to assist him in cheating and to counter PAW Patrol.