Bayleef

Bayleef is the only conceivably viable Grass-type that gets both Light Screen and Reflect. This, along with its status as one of the mere handful of Pokemon that has these moves, much less can afford to run them, grants Bayleef a unique niche in NU. It has quite a bit of natural bulk, and mono-Grass typing is usually useful in a tier full of Water-types. However, Bayleef's niche isn't always that useful in a tier that punishes passive Pokemon like itself with setup and is dominated by Toxic. Bayleef is also almost strictly outclassed by Wigglytuff as a straight dual screens setter, and the only major benefits to running it are it checking Huntail and having a better defensive typing. Furthermore, while Bayleef may be bulky, it has no offensive presence, gets shut down by Taunt, is neutered by Encore, and is easily taken advantage of. Bayleef is best used to set up dual screens quickly and allow a teammate to set up at reduced risk. The only reason you would ever consider running Bayleef is for Light Screen. Otherwise, just use Bellossom or Tangela for a Grass-type.