I was thinking about nominating Shuckle, then I decided not to since it's BL2, then I remembered that it does have an Ubers analysis, so here we go!
Shuckle for
A rank.
Shuckle is an adorable blob trapped inside an adorable shell with holes in it. It's a very important Pokemon for supporting the cuteness of other Pokemon by making sure each and every monster on the opposing side is trapped by its cute webs and rocks, making even Ferrothorn cute in comparison to opposing monsters. Because of its Sturdy ability, it's also cute enough to take many ridiculously cute attacks; only Mama-Kangaskhan can prevent it from showing off how adorable it is. However, the reason I'm not nominating it for H rank is because it does have two major flaws. First, it's easily Taunted into doing un-cute things like attacking or switching. However, this is mitigated by certain held items; Shuckle will nearly always get a chance to support its cute allies with a Mental Herb. Next, as a cute support Pokemon, it's forced to rely on other teammates who might not be as cute, which is why you should use other cute teammates like Groudon who would appreciate the support to shine even further. However, entire teams are built around utilizing Shuckle's cuteness to the max, so it could very well become H under that condition.
Just look at it.