The technique to make Clobbopus evolve in Grapploct is quite simple.
Especially since you can catch Grapploct directly in the wild.
Route 9 is the ideal place to find Clobbopus and Grapploct.
How to make Clobbopus evolve?
First of all, your Clobbopus must know the Taunt move.
Once he knows this move, you have to level up.