I used Serperior as a SubSeeder for a while last round to decent effect, but that was with the larger presence of water Pokemon that it could easily set up on. I think Jumpluff is better for SubSeeding this round simply because it's a hell of a lot faster and has Encore to be even more annoying.
Meganium is probably a better supporting Grass-type due to a wider supporting movepool, but its speed is pretty bad. The few things it gets that Serperior doesn't get are really the only things you should ever use it for in my opinion.
Meganium is probably a better supporting Grass-type due to a wider supporting movepool, but its speed is pretty bad. The few things it gets that Serperior doesn't get are really the only things you should ever use it for in my opinion.