[yee]

I really, really like this team. Zapdos and Tangrowth are two mons I feel have been extremely underrated even since BW1, especially Tangrowth which IMO is safe to call a full-on Physical Blissey. Anyway...

252 HP / 252 Def on Forry blows, there's a certain point where you get so little out of every defense EV and so much out of each special defense EV that it becomes nonsensical to go any further doing so. This point was passed way before you got up to max defense IMO, if you trust my intuition (and you should) I would recommend using 252 HP / 136 Def (jump point) / 120 SpD instead. I was recently working on a team that had been filled out with full defense before and made that spread with the intention of keeping it in the exact same role, but to be still be as effective overall as possible. What happened the first game was a Kyurem-B alternating between Fusion Bolt and Ice Beam (doing about the same amount of damage) and me surviving it's final blow with 4% to spare- this allowed me to play the particular game safely. I have no doubt it was guaranteed to be KOed by Ice Beam that one turn earlier which would've replaced my optimal situation with possibly an even game. Hopefully you'll have similar experiences immediately, if not I'm absolutely sure you'll love it's ability to take a resisted Ice Beam at some point.

Let's apply this to Tangrowth too. I personally would recommend the exact same spread there (252 / 136 / 120), or even more specially oriented, for the same reasons. It will one day end up in a situation where it will have to eat an HP Ice and it will be obviously more able to do so with this spread, it will also not immediately fold to things like Specs Starmie Hydro Pump in rain or a Life Orb Starmie Ice Beam outside of it (although you'll need to be super healthy for the Ice Beam case). It will still do a splendid job cushioning Choice Banded attacks and Forretress / Jellicent / Zapdos will be just as good at resisting. If stall is bothering you for whatever reason, try adding Knock Off for extra residual, if offense is trouble keep as is IMO.

For Jellicent, why are you running Calm? I've never understood why anyone has specifically run Calm. It only takes 36 ish from SpD Rotom-W V-switch Bold and will tank anything significant but a Thunder from Thund-T / Rotom-W, which I guess warrants a small case, though I still feel it's not worth it given how squishy it is physically there. I like the extra security vs Scizor / ScarfTar / anything physical whenever I can grab it, but it's a bit more subjective than my previous nitpicks. If you are annoyed by SubToxic Tentacruel, try out Rest > Taunt. Jellicent is a mon you can fuck around with a lot, as long as you have Will-o-Wisp and Recover you are good to go! It may seem like giving up Taunt is giving up a key piece but only ladder players will generally immediately assume you are lacking Taunt (they really do this every single time) and the reward for assuming your opponent plays it safe is trolling their Tentacruel with REST of all things. I know its BW2 but have some fun here. Don't be afraid to jump up to Timid with enough speed to outrun Adamant Band Tar if you'd really like to and don't be afraid to try Cursed Body- this effectively destroys the opponents chances of critting you to death when they are so much more likely to get disabled than get their hit.

Lastly I prefer Impish on my Hippo because it's already tanking Specs Hydreigon Draco Meteors and taking on Sub Hydreigon no problem. I feel like there's no significant cost and that extra buffer physically to gain.

Good luck, have fun. Pray they make this metagame less of a failed abortion.