It's name is Clobbopus and just look at the little idiot. Look at those adorable little MMA mittens.
It's evolution, Grapploct is basically Minoru Suzuki and that's terrifying, not a fan of the colour scheme but it looks better in a shiny (its white and purple, I think). Using your own tentacle as a title belt is pretty insane. Still, another one I prefer in its unevolved form.
Here's the ridiculous thing though, you encounter Grapploct BEFORE you encounter Clobbopus, they only start appearing in the same late game route but you find them in the wrong order. Absolute screw job they're doing on this little guy. It's Tangela syndrome all over again. Currently breeding a load of Clobbopus to take over the world. Why would you put this on the second to last route? Gamefreak are dumb.