Welp, here it is guys, once Rotgrub levels up knowing Acid Spray, it becomes Revolfly (revolting/ revolver + fly)! It is based on the Rabbit Botfly and old western style sheriffs.
I'd also like to note that this was inspired in part by @turtwigpokefusions's fusion of Steelix and Scolipede. The resulting fusion had a Steel/Poison typing that made me want to create a fakemon with the type combo. c: