Similar to a country bumpkin a whomper is a loud obnoxious sometimes rowdy person known to be silly making jokes and causing a scene. Most likely comes from a smaller town, lower class and have a simple job and means of life.
Those jolly whompers in Slayton, MN are always hanging out around the bar never having a place they need to be.
Relating to the word "Whomp" but in the form of a physical being. When there are no other words that could possiblysummarize how much energy and joy a thing/person drains from you.
"I really thought I was gonna enjoy Evil Dead Rise, but it ended up being a total whomper!"