Shuckle

Last generation, Shuckle was stuck in NU, incapable of doing much besides sitting around and Toxic stalling until it fainted. But when XY came around, Shuckle got access to a rare and unique move: Sticky Web. Being the most reliable user of Sticky Web is a small but valuable niche that no other Pokemon in the metagame can boast. This, along with its useful access to Stealth Rock, allows Shuckle to see the light of OU. Despite having no offensive presence, Shuckle cannot be set up on thanks to its access to Encore.

However, don't be fooled into thinking Shuckle is a flawless Pokemon. Its base 230 defenses are offset by a terrible base 20 HP, meaning that Shuckle isn't as bulky as it seems. It is crippled by Taunt and Trick, though the former is somewhat remedied by Mental Herb. Weaknesses to common Water-, Rock-, and Steel-type moves, along with no reliable recovery, mean that Shuckle won't be staying for long. It will always be moving last because of its nonexistent base 5 Speed, which means that it will have to take a hit before doing anything. It is essentially a sitting duck on the battlefield, and it has to rely on Toxic or Infestation to do any damage. It also receives competition from Smeargle as a Sticky Web user, as it gets Magic Coat to ward off Taunt and Spore to provide opportunities to set up Sticky Web. However, Shuckle is much bulkier and much more reliable than Smeargle, and can't be set up on. Despite these shortcomings, Shuckle provides valuable support to Sticky Web teams, and in the right hands, can be a thorn in your opponent's side.