Pic related you can only find in Victory road. Same with Druddigon. A lot of 2 stage evo pokemon like Garbador, Muk, Wheezing, Seaking, etc also evolve when they're in their lvl 30s-40s.

I think trashmons are endearing for single player gameplay. But you have to get out of your way trading in trashmon eggs from another save file. I'm so tired of the cliche Route 1 rats, route 1 birds & route 2 bugs early game.